Mixing
Engineers logic test for a job
Clash Royale CLAN TAG#URR8PPP
up vote
4
down vote
favorite
Two engineers go to a job interview. They are introduced and told they are looking for people with team working skills. Without time to talk or get to know each other, they are guided to two different rooms with a window from which they see a wind turbine park.
Engineer A can see 22 turbines.
Engineer B can see 4 turbines.
They are told that in the park there are 24 or 26 turbines, none of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park.
During the next hours, an interviewer will ask them a question per round, always being the same question. He will ask first to engineer A, and, if he does not answer, will then ask to engineer B. The question is: "Are there 24, or 26 turbines in the park?".
If one of the engineers answer correctly, both are hired.
If one answer incorrectly, none will be hired.
If there's no answer, the interviewer will go ask the next engineer, starting a round of "question to engineer A - question to engineer B", always starting by engineer A.
Knowing that both consider they are very logic people and really want the job: In how many rounds will they manage to answer correctly, without any doubt, if possible?
EDIT: Oras found this puzzle asked 2 years ago (with a different story) here, however since the numbers differ and it's rather old I will keep the post. By the way, this is my first post here, glad to be part of the community!
logical-deduction meta-knowledge
asked 1 hour ago
Evaldor
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
 |Â
show 5 more comments
up vote
4
down vote
favorite
Two engineers go to a job interview. They are introduced and told they are looking for people with team working skills. Without time to talk or get to know each other, they are guided to two different rooms with a window from which they see a wind turbine park.
Engineer A can see 22 turbines.
Engineer B can see 4 turbines.
They are told that in the park there are 24 or 26 turbines, none of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park.
During the next hours, an interviewer will ask them a question per round, always being the same question. He will ask first to engineer A, and, if he does not answer, will then ask to engineer B. The question is: "Are there 24, or 26 turbines in the park?".
If one of the engineers answer correctly, both are hired.
If one answer incorrectly, none will be hired.
If there's no answer, the interviewer will go ask the next engineer, starting a round of "question to engineer A - question to engineer B", always starting by engineer A.
Knowing that both consider they are very logic people and really want the job: In how many rounds will they manage to answer correctly, without any doubt, if possible?
EDIT: Oras found this puzzle asked 2 years ago (with a different story) here, however since the numbers differ and it's rather old I will keep the post. By the way, this is my first post here, glad to be part of the community!
logical-deduction meta-knowledge
asked 1 hour ago
Evaldor
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Is it possible for the engineers to come up with a strategy before the interviewer starts asking them questions, or not?
– Excited Raichu
1 hour ago
wait never mind didn’t read close enough
– Excited Raichu
1 hour ago
Is it possible, that one of them does not see any turbines?
– Torsten Link
53 mins ago
"None of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park." Acording to this it could be possible, indeed. But in this instance they see 22 - 4.
– Evaldor
48 mins ago
1
this is duplicate of a question asked before, cant find it yet :)
– Oray
32 mins ago
 |Â
show 5 more comments
up vote
4
down vote
favorite
up vote
4
down vote
favorite
Two engineers go to a job interview. They are introduced and told they are looking for people with team working skills. Without time to talk or get to know each other, they are guided to two different rooms with a window from which they see a wind turbine park.
Engineer A can see 22 turbines.
Engineer B can see 4 turbines.
They are told that in the park there are 24 or 26 turbines, none of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park.
During the next hours, an interviewer will ask them a question per round, always being the same question. He will ask first to engineer A, and, if he does not answer, will then ask to engineer B. The question is: "Are there 24, or 26 turbines in the park?".
If one of the engineers answer correctly, both are hired.
If one answer incorrectly, none will be hired.
If there's no answer, the interviewer will go ask the next engineer, starting a round of "question to engineer A - question to engineer B", always starting by engineer A.
Knowing that both consider they are very logic people and really want the job: In how many rounds will they manage to answer correctly, without any doubt, if possible?
EDIT: Oras found this puzzle asked 2 years ago (with a different story) here, however since the numbers differ and it's rather old I will keep the post. By the way, this is my first post here, glad to be part of the community!
logical-deduction meta-knowledge
asked 1 hour ago
Evaldor
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Two engineers go to a job interview. They are introduced and told they are looking for people with team working skills. Without time to talk or get to know each other, they are guided to two different rooms with a window from which they see a wind turbine park.
Engineer A can see 22 turbines.
Engineer B can see 4 turbines.
They are told that in the park there are 24 or 26 turbines, none of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park.
During the next hours, an interviewer will ask them a question per round, always being the same question. He will ask first to engineer A, and, if he does not answer, will then ask to engineer B. The question is: "Are there 24, or 26 turbines in the park?".
If one of the engineers answer correctly, both are hired.
If one answer incorrectly, none will be hired.
If there's no answer, the interviewer will go ask the next engineer, starting a round of "question to engineer A - question to engineer B", always starting by engineer A.
Knowing that both consider they are very logic people and really want the job: In how many rounds will they manage to answer correctly, without any doubt, if possible?
EDIT: Oras found this puzzle asked 2 years ago (with a different story) here, however since the numbers differ and it's rather old I will keep the post. By the way, this is my first post here, glad to be part of the community!
logical-deduction meta-knowledge
logical-deduction meta-knowledge
asked 1 hour ago
Evaldor
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 1 hour ago
Evaldor
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 4 mins ago
asked 1 hour ago
Evaldor
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 1 hour ago
Evaldor
234
asked 1 hour ago
Evaldor
234
234
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Evaldor is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Is it possible for the engineers to come up with a strategy before the interviewer starts asking them questions, or not?
– Excited Raichu
1 hour ago
wait never mind didn’t read close enough
– Excited Raichu
1 hour ago
Is it possible, that one of them does not see any turbines?
– Torsten Link
53 mins ago
"None of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park." Acording to this it could be possible, indeed. But in this instance they see 22 - 4.
– Evaldor
48 mins ago
1
this is duplicate of a question asked before, cant find it yet :)
– Oray
32 mins ago
 |Â
show 5 more comments
Is it possible for the engineers to come up with a strategy before the interviewer starts asking them questions, or not?
– Excited Raichu
1 hour ago
wait never mind didn’t read close enough
– Excited Raichu
1 hour ago
Is it possible, that one of them does not see any turbines?
– Torsten Link
53 mins ago
"None of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park." Acording to this it could be possible, indeed. But in this instance they see 22 - 4.
– Evaldor
48 mins ago
1
this is duplicate of a question asked before, cant find it yet :)
– Oray
32 mins ago
Is it possible for the engineers to come up with a strategy before the interviewer starts asking them questions, or not?
– Excited Raichu
1 hour ago
Is it possible for the engineers to come up with a strategy before the interviewer starts asking them questions, or not?
– Excited Raichu
1 hour ago
wait never mind didn’t read close enough
– Excited Raichu
1 hour ago
wait never mind didn’t read close enough
– Excited Raichu
1 hour ago
Is it possible, that one of them does not see any turbines?
– Torsten Link
53 mins ago
Is it possible, that one of them does not see any turbines?
– Torsten Link
53 mins ago
"None of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park." Acording to this it could be possible, indeed. But in this instance they see 22 - 4.
– Evaldor
48 mins ago
"None of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park." Acording to this it could be possible, indeed. But in this instance they see 22 - 4.
– Evaldor
48 mins ago
1
1
this is duplicate of a question asked before, cant find it yet :)
– Oray
32 mins ago
this is duplicate of a question asked before, cant find it yet :)
– Oray
32 mins ago
 |Â
show 5 more comments
3 Answers
3
active
oldest
votes
up vote
1
down vote
accepted
Answer
$A$ will know how many there are in the third round of questions.
Consider some simpler versions of the problem first
Case 1
There are $26$ turbines.
$A$ can see $24$ and $B$ can see $2$ and they are both told that there are either $24$ or $26$.
First round
$A$ doesn't know but does know that $B$ either sees $0$ or $2$ turbines.
If $B$ sees $0$, then, by the fact that $A$ doesn't know, $B$ would know that $A$ cannot see $26$ (otherwise $A$ would know there are not $24$).
Because $B$ sees $2$, they say that they don't know.
Second round
$A$ now knows that $B$ does not see $0$ turbines and must see $2$ so $A$ knows that there are $26$ turbines.
Now consider a slightly different set-up
Case 2
There are $24$ turbines.
$A$ can see $22$ turbines and $B$ can see $2$ turbines and they are both told that there are either $24$ or $26$ turbines.
Notice that the situation, from $B$'s perspective, is exactly the same as in Case 1 and $B$ will suppose that $A$ sees either $22$ or $24$ turbines. Thus, we get the following
First Round
$A$ doesn't know. $B$ doesn't know.
Second Round
$A$ says they don't know.
$B$ now realises that $A$ does not have $24$ turbines, otherwise we would be in Case 1 and $A$ would know how many turbines there are. Hence, $A$ must see $22$ turbines and $B$ knows the overall number to be $24$.
Case 3 (the current case)
There are $26$ turbines
$A$ sees $22$ and $B$ sees $4$. Notice that, from $A$'s perspective the scenario is the same as in Case 2 and $A$ knows that $B$ can see either $2$ or $4$ turbines. The questioning proceeds as follows
First Round
$A$ doesn't know., $B$ doesn't know.
Second Round
$A$ doesn't know., $B$ doesn't know.
Third Round
Because $B$ doesn't know in the second round, $A$ knows that $B$ does not see $2$ turbines (otherwise we are in Case 2). Hence, $A$ knows there must be $26$ turbines.
answered 47 mins ago
hexomino
31.1k293150
This is correct :)
– Evaldor
14 mins ago
add a comment |Â
up vote
1
down vote
I will try:
A knows that B has 2 or 4 and B knows that A sees 20 or 22
But lets forget about that for a moment.
2. A does not say anything, so B knows, that he did not see 25 or 26 turbines as then 24 would not be possible anymore and he could instantly answer.
So then
3. B himself does not say something, so A knows: He doesn't have 0 or 1, because otherwise he would have known from 2. that it must be 24.
After that
4. A still doesn't know, if B has 2 oder 4, so he says nothing.
Next step:
5. B knows: If A had 24, then he would have known, there are 26 turbines (as 3. states, that B cannot have seen 0 turbines) and would have answered: A does NOT have 24... B still does not answer
And finally
6. A knows: If B had 2, then he knew from 5. that it cannot be 26 and would answer 24. So finally A knows: B saw 4 and can answer correctly.
answered 33 mins ago
Torsten Link
31114
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
you are right.... argh
– Torsten Link
14 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
Now it's correct!
– Evaldor
1 min ago
add a comment |Â
up vote
0
down vote
So, let’s start with what each engineer knows about the other:
Engineer A knows that
engineer B sees either 2 or 4 turbines.
In addition, Engineer B knows that
engineer A sees either 20 or 22 turbines.
So, round 1 begins,
and A has no way to know how many turbines B saw (2 or 4), so they pass.
Then it’s B’s turn, and
they now know some new information. B knows that A thinks that B has either 2, 4, or 6 turbines. If B had 6 turbines, he/she would be able to guess 26 on this turn, because B knows that either A has 20 or 22 turbines, and A must have 20 (because 28 is too many.) B now knows that A thinks that B has either 2 or 4 turbines (because A can use this logic as well). If A had 20 turbines, A could guess 24 using this logic (because 22 is too few). So, B knows that A has 22 turbines,
and therefore,
B guesses 26, turn 1.
answered 46 mins ago
Excited Raichu
70913
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
add a comment |Â
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
accepted
Answer
$A$ will know how many there are in the third round of questions.
Consider some simpler versions of the problem first
Case 1
There are $26$ turbines.
$A$ can see $24$ and $B$ can see $2$ and they are both told that there are either $24$ or $26$.
First round
$A$ doesn't know but does know that $B$ either sees $0$ or $2$ turbines.
If $B$ sees $0$, then, by the fact that $A$ doesn't know, $B$ would know that $A$ cannot see $26$ (otherwise $A$ would know there are not $24$).
Because $B$ sees $2$, they say that they don't know.
Second round
$A$ now knows that $B$ does not see $0$ turbines and must see $2$ so $A$ knows that there are $26$ turbines.
Now consider a slightly different set-up
Case 2
There are $24$ turbines.
$A$ can see $22$ turbines and $B$ can see $2$ turbines and they are both told that there are either $24$ or $26$ turbines.
Notice that the situation, from $B$'s perspective, is exactly the same as in Case 1 and $B$ will suppose that $A$ sees either $22$ or $24$ turbines. Thus, we get the following
First Round
$A$ doesn't know. $B$ doesn't know.
Second Round
$A$ says they don't know.
$B$ now realises that $A$ does not have $24$ turbines, otherwise we would be in Case 1 and $A$ would know how many turbines there are. Hence, $A$ must see $22$ turbines and $B$ knows the overall number to be $24$.
Case 3 (the current case)
There are $26$ turbines
$A$ sees $22$ and $B$ sees $4$. Notice that, from $A$'s perspective the scenario is the same as in Case 2 and $A$ knows that $B$ can see either $2$ or $4$ turbines. The questioning proceeds as follows
First Round
$A$ doesn't know., $B$ doesn't know.
Second Round
$A$ doesn't know., $B$ doesn't know.
Third Round
Because $B$ doesn't know in the second round, $A$ knows that $B$ does not see $2$ turbines (otherwise we are in Case 2). Hence, $A$ knows there must be $26$ turbines.
answered 47 mins ago
hexomino
31.1k293150
This is correct :)
– Evaldor
14 mins ago
add a comment |Â
up vote
1
down vote
accepted
Answer
$A$ will know how many there are in the third round of questions.
Consider some simpler versions of the problem first
Case 1
There are $26$ turbines.
$A$ can see $24$ and $B$ can see $2$ and they are both told that there are either $24$ or $26$.
First round
$A$ doesn't know but does know that $B$ either sees $0$ or $2$ turbines.
If $B$ sees $0$, then, by the fact that $A$ doesn't know, $B$ would know that $A$ cannot see $26$ (otherwise $A$ would know there are not $24$).
Because $B$ sees $2$, they say that they don't know.
Second round
$A$ now knows that $B$ does not see $0$ turbines and must see $2$ so $A$ knows that there are $26$ turbines.
Now consider a slightly different set-up
Case 2
There are $24$ turbines.
$A$ can see $22$ turbines and $B$ can see $2$ turbines and they are both told that there are either $24$ or $26$ turbines.
Notice that the situation, from $B$'s perspective, is exactly the same as in Case 1 and $B$ will suppose that $A$ sees either $22$ or $24$ turbines. Thus, we get the following
First Round
$A$ doesn't know. $B$ doesn't know.
Second Round
$A$ says they don't know.
$B$ now realises that $A$ does not have $24$ turbines, otherwise we would be in Case 1 and $A$ would know how many turbines there are. Hence, $A$ must see $22$ turbines and $B$ knows the overall number to be $24$.
Case 3 (the current case)
There are $26$ turbines
$A$ sees $22$ and $B$ sees $4$. Notice that, from $A$'s perspective the scenario is the same as in Case 2 and $A$ knows that $B$ can see either $2$ or $4$ turbines. The questioning proceeds as follows
First Round
$A$ doesn't know., $B$ doesn't know.
Second Round
$A$ doesn't know., $B$ doesn't know.
Third Round
Because $B$ doesn't know in the second round, $A$ knows that $B$ does not see $2$ turbines (otherwise we are in Case 2). Hence, $A$ knows there must be $26$ turbines.
answered 47 mins ago
hexomino
31.1k293150
This is correct :)
– Evaldor
14 mins ago
add a comment |Â
up vote
1
down vote
accepted
up vote
1
down vote
accepted
Answer
$A$ will know how many there are in the third round of questions.
Consider some simpler versions of the problem first
Case 1
There are $26$ turbines.
$A$ can see $24$ and $B$ can see $2$ and they are both told that there are either $24$ or $26$.
First round
$A$ doesn't know but does know that $B$ either sees $0$ or $2$ turbines.
If $B$ sees $0$, then, by the fact that $A$ doesn't know, $B$ would know that $A$ cannot see $26$ (otherwise $A$ would know there are not $24$).
Because $B$ sees $2$, they say that they don't know.
Second round
$A$ now knows that $B$ does not see $0$ turbines and must see $2$ so $A$ knows that there are $26$ turbines.
Now consider a slightly different set-up
Case 2
There are $24$ turbines.
$A$ can see $22$ turbines and $B$ can see $2$ turbines and they are both told that there are either $24$ or $26$ turbines.
Notice that the situation, from $B$'s perspective, is exactly the same as in Case 1 and $B$ will suppose that $A$ sees either $22$ or $24$ turbines. Thus, we get the following
First Round
$A$ doesn't know. $B$ doesn't know.
Second Round
$A$ says they don't know.
$B$ now realises that $A$ does not have $24$ turbines, otherwise we would be in Case 1 and $A$ would know how many turbines there are. Hence, $A$ must see $22$ turbines and $B$ knows the overall number to be $24$.
Case 3 (the current case)
There are $26$ turbines
$A$ sees $22$ and $B$ sees $4$. Notice that, from $A$'s perspective the scenario is the same as in Case 2 and $A$ knows that $B$ can see either $2$ or $4$ turbines. The questioning proceeds as follows
First Round
$A$ doesn't know., $B$ doesn't know.
Second Round
$A$ doesn't know., $B$ doesn't know.
Third Round
Because $B$ doesn't know in the second round, $A$ knows that $B$ does not see $2$ turbines (otherwise we are in Case 2). Hence, $A$ knows there must be $26$ turbines.
answered 47 mins ago
hexomino
31.1k293150
Answer
$A$ will know how many there are in the third round of questions.
Consider some simpler versions of the problem first
Case 1
There are $26$ turbines.
$A$ can see $24$ and $B$ can see $2$ and they are both told that there are either $24$ or $26$.
First round
$A$ doesn't know but does know that $B$ either sees $0$ or $2$ turbines.
If $B$ sees $0$, then, by the fact that $A$ doesn't know, $B$ would know that $A$ cannot see $26$ (otherwise $A$ would know there are not $24$).
Because $B$ sees $2$, they say that they don't know.
Second round
$A$ now knows that $B$ does not see $0$ turbines and must see $2$ so $A$ knows that there are $26$ turbines.
Now consider a slightly different set-up
Case 2
There are $24$ turbines.
$A$ can see $22$ turbines and $B$ can see $2$ turbines and they are both told that there are either $24$ or $26$ turbines.
Notice that the situation, from $B$'s perspective, is exactly the same as in Case 1 and $B$ will suppose that $A$ sees either $22$ or $24$ turbines. Thus, we get the following
First Round
$A$ doesn't know. $B$ doesn't know.
Second Round
$A$ says they don't know.
$B$ now realises that $A$ does not have $24$ turbines, otherwise we would be in Case 1 and $A$ would know how many turbines there are. Hence, $A$ must see $22$ turbines and $B$ knows the overall number to be $24$.
Case 3 (the current case)
There are $26$ turbines
$A$ sees $22$ and $B$ sees $4$. Notice that, from $A$'s perspective the scenario is the same as in Case 2 and $A$ knows that $B$ can see either $2$ or $4$ turbines. The questioning proceeds as follows
First Round
$A$ doesn't know., $B$ doesn't know.
Second Round
$A$ doesn't know., $B$ doesn't know.
Third Round
Because $B$ doesn't know in the second round, $A$ knows that $B$ does not see $2$ turbines (otherwise we are in Case 2). Hence, $A$ knows there must be $26$ turbines.
answered 47 mins ago
hexomino
31.1k293150
answered 47 mins ago
hexomino
31.1k293150
answered 47 mins ago
hexomino
31.1k293150
answered 47 mins ago
hexomino
31.1k293150
31.1k293150
This is correct :)
– Evaldor
14 mins ago
add a comment |Â
This is correct :)
– Evaldor
14 mins ago
This is correct :)
– Evaldor
14 mins ago
This is correct :)
– Evaldor
14 mins ago
add a comment |Â
up vote
1
down vote
I will try:
A knows that B has 2 or 4 and B knows that A sees 20 or 22
But lets forget about that for a moment.
2. A does not say anything, so B knows, that he did not see 25 or 26 turbines as then 24 would not be possible anymore and he could instantly answer.
So then
3. B himself does not say something, so A knows: He doesn't have 0 or 1, because otherwise he would have known from 2. that it must be 24.
After that
4. A still doesn't know, if B has 2 oder 4, so he says nothing.
Next step:
5. B knows: If A had 24, then he would have known, there are 26 turbines (as 3. states, that B cannot have seen 0 turbines) and would have answered: A does NOT have 24... B still does not answer
And finally
6. A knows: If B had 2, then he knew from 5. that it cannot be 26 and would answer 24. So finally A knows: B saw 4 and can answer correctly.
answered 33 mins ago
Torsten Link
31114
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
you are right.... argh
– Torsten Link
14 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
Now it's correct!
– Evaldor
1 min ago
add a comment |Â
up vote
1
down vote
I will try:
A knows that B has 2 or 4 and B knows that A sees 20 or 22
But lets forget about that for a moment.
2. A does not say anything, so B knows, that he did not see 25 or 26 turbines as then 24 would not be possible anymore and he could instantly answer.
So then
3. B himself does not say something, so A knows: He doesn't have 0 or 1, because otherwise he would have known from 2. that it must be 24.
After that
4. A still doesn't know, if B has 2 oder 4, so he says nothing.
Next step:
5. B knows: If A had 24, then he would have known, there are 26 turbines (as 3. states, that B cannot have seen 0 turbines) and would have answered: A does NOT have 24... B still does not answer
And finally
6. A knows: If B had 2, then he knew from 5. that it cannot be 26 and would answer 24. So finally A knows: B saw 4 and can answer correctly.
answered 33 mins ago
Torsten Link
31114
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
you are right.... argh
– Torsten Link
14 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
Now it's correct!
– Evaldor
1 min ago
add a comment |Â
up vote
1
down vote
up vote
1
down vote
I will try:
A knows that B has 2 or 4 and B knows that A sees 20 or 22
But lets forget about that for a moment.
2. A does not say anything, so B knows, that he did not see 25 or 26 turbines as then 24 would not be possible anymore and he could instantly answer.
So then
3. B himself does not say something, so A knows: He doesn't have 0 or 1, because otherwise he would have known from 2. that it must be 24.
After that
4. A still doesn't know, if B has 2 oder 4, so he says nothing.
Next step:
5. B knows: If A had 24, then he would have known, there are 26 turbines (as 3. states, that B cannot have seen 0 turbines) and would have answered: A does NOT have 24... B still does not answer
And finally
6. A knows: If B had 2, then he knew from 5. that it cannot be 26 and would answer 24. So finally A knows: B saw 4 and can answer correctly.
answered 33 mins ago
Torsten Link
31114
I will try:
A knows that B has 2 or 4 and B knows that A sees 20 or 22
But lets forget about that for a moment.
2. A does not say anything, so B knows, that he did not see 25 or 26 turbines as then 24 would not be possible anymore and he could instantly answer.
So then
3. B himself does not say something, so A knows: He doesn't have 0 or 1, because otherwise he would have known from 2. that it must be 24.
After that
4. A still doesn't know, if B has 2 oder 4, so he says nothing.
Next step:
5. B knows: If A had 24, then he would have known, there are 26 turbines (as 3. states, that B cannot have seen 0 turbines) and would have answered: A does NOT have 24... B still does not answer
And finally
6. A knows: If B had 2, then he knew from 5. that it cannot be 26 and would answer 24. So finally A knows: B saw 4 and can answer correctly.
answered 33 mins ago
Torsten Link
31114
edited 8 mins ago
answered 33 mins ago
Torsten Link
31114
answered 33 mins ago
Torsten Link
31114
answered 33 mins ago
Torsten Link
31114
31114
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
you are right.... argh
– Torsten Link
14 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
Now it's correct!
– Evaldor
1 min ago
add a comment |Â
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
you are right.... argh
– Torsten Link
14 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
Now it's correct!
– Evaldor
1 min ago
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
"1. A knows that B has 2 or 4 and B knows that A sees 22 or 24". Are you sure? Check those numbers :)
– Evaldor
16 mins ago
you are right.... argh
– Torsten Link
14 mins ago
you are right.... argh
– Torsten Link
14 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
fixed it... one more step necessary
– Torsten Link
8 mins ago
Now it's correct!
– Evaldor
1 min ago
Now it's correct!
– Evaldor
1 min ago
add a comment |Â
up vote
0
down vote
So, let’s start with what each engineer knows about the other:
Engineer A knows that
engineer B sees either 2 or 4 turbines.
In addition, Engineer B knows that
engineer A sees either 20 or 22 turbines.
So, round 1 begins,
and A has no way to know how many turbines B saw (2 or 4), so they pass.
Then it’s B’s turn, and
they now know some new information. B knows that A thinks that B has either 2, 4, or 6 turbines. If B had 6 turbines, he/she would be able to guess 26 on this turn, because B knows that either A has 20 or 22 turbines, and A must have 20 (because 28 is too many.) B now knows that A thinks that B has either 2 or 4 turbines (because A can use this logic as well). If A had 20 turbines, A could guess 24 using this logic (because 22 is too few). So, B knows that A has 22 turbines,
and therefore,
B guesses 26, turn 1.
answered 46 mins ago
Excited Raichu
70913
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
add a comment |Â
up vote
0
down vote
So, let’s start with what each engineer knows about the other:
Engineer A knows that
engineer B sees either 2 or 4 turbines.
In addition, Engineer B knows that
engineer A sees either 20 or 22 turbines.
So, round 1 begins,
and A has no way to know how many turbines B saw (2 or 4), so they pass.
Then it’s B’s turn, and
they now know some new information. B knows that A thinks that B has either 2, 4, or 6 turbines. If B had 6 turbines, he/she would be able to guess 26 on this turn, because B knows that either A has 20 or 22 turbines, and A must have 20 (because 28 is too many.) B now knows that A thinks that B has either 2 or 4 turbines (because A can use this logic as well). If A had 20 turbines, A could guess 24 using this logic (because 22 is too few). So, B knows that A has 22 turbines,
and therefore,
B guesses 26, turn 1.
answered 46 mins ago
Excited Raichu
70913
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
add a comment |Â
up vote
0
down vote
up vote
0
down vote
So, let’s start with what each engineer knows about the other:
Engineer A knows that
engineer B sees either 2 or 4 turbines.
In addition, Engineer B knows that
engineer A sees either 20 or 22 turbines.
So, round 1 begins,
and A has no way to know how many turbines B saw (2 or 4), so they pass.
Then it’s B’s turn, and
they now know some new information. B knows that A thinks that B has either 2, 4, or 6 turbines. If B had 6 turbines, he/she would be able to guess 26 on this turn, because B knows that either A has 20 or 22 turbines, and A must have 20 (because 28 is too many.) B now knows that A thinks that B has either 2 or 4 turbines (because A can use this logic as well). If A had 20 turbines, A could guess 24 using this logic (because 22 is too few). So, B knows that A has 22 turbines,
and therefore,
B guesses 26, turn 1.
answered 46 mins ago
Excited Raichu
70913
So, let’s start with what each engineer knows about the other:
Engineer A knows that
engineer B sees either 2 or 4 turbines.
In addition, Engineer B knows that
engineer A sees either 20 or 22 turbines.
So, round 1 begins,
and A has no way to know how many turbines B saw (2 or 4), so they pass.
Then it’s B’s turn, and
they now know some new information. B knows that A thinks that B has either 2, 4, or 6 turbines. If B had 6 turbines, he/she would be able to guess 26 on this turn, because B knows that either A has 20 or 22 turbines, and A must have 20 (because 28 is too many.) B now knows that A thinks that B has either 2 or 4 turbines (because A can use this logic as well). If A had 20 turbines, A could guess 24 using this logic (because 22 is too few). So, B knows that A has 22 turbines,
and therefore,
B guesses 26, turn 1.
answered 46 mins ago
Excited Raichu
70913
answered 46 mins ago
Excited Raichu
70913
answered 46 mins ago
Excited Raichu
70913
answered 46 mins ago
Excited Raichu
70913
70913
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
add a comment |Â
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
If A sees 20 turbines then A would suppose that B sees 4 or 6 (not 2 or 4) so they would not be able to guess 24 as you say in the last line of the 4th paragraph. Consider the scenario where A sees 20 turbines instead of 22. What changes from Bs perspective?
– hexomino
18 mins ago
add a comment |Â
Evaldor is a new contributor. Be nice, and check out our Code of Conduct.
Evaldor is a new contributor. Be nice, and check out our Code of Conduct.
Evaldor is a new contributor. Be nice, and check out our Code of Conduct.
Evaldor is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f73462%2fengineers-logic-test-for-a-job%23new-answer', 'question_page');
);
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Is it possible for the engineers to come up with a strategy before the interviewer starts asking them questions, or not?
– Excited Raichu
1 hour ago
wait never mind didn’t read close enough
– Excited Raichu
1 hour ago
Is it possible, that one of them does not see any turbines?
– Torsten Link
53 mins ago
"None of them are seen by both engineers at the same time, and between the two they can see all the turbines in the park." Acording to this it could be possible, indeed. But in this instance they see 22 - 4.
– Evaldor
48 mins ago
1
this is duplicate of a question asked before, cant find it yet :)
– Oray
32 mins ago