Labs247 Interview Question
Quality Assurance EngineersCountry: India
Interview Type: In-Person
When A said he doesn't know :
-> botch B and C are not wearing white.
When B saw C, if C had a white cap B would have answered black because from A's answer both B and C were sure both of them are not wearing white cap.
So when B said he doesn't know C was sure he was wearing a black cap.
When A says he doesn't know it means that he doesn't see two white caps. That means he sees
1. Two black caps
OR
2. One white cap and one black cap
In that context B knows that he's wearing a black cap if he sees C wearing a white cap. If B were to see C wearing a black cap he (B) wouldn't know the color of his cap. That is based on implications from A's answer.
Since B says he doesn't know the color of his cap it means that C wears a black cap.
When A said he doesnt know he means that the two guys infront of him are wearing black caps. As there are three black caps he could be wearing either black or white.
Is my logic correct?
A B C
----------------
B B B
B B W - Ruled Out By B in Step 2.
B W B
B W W-{ Step 1:A's Turn: Decision1 : if this was the case . A would have said he is
wearing While, so this wasn't case, this option is ruled out , B can use this fact
when he makes a decision }
W B B { Step 2: B's Turn: When ever C is wearing White B is wearing Black, B would
have said he is wearing Block If C is wearing White , But this wasn't the case ,
therefore option 2 and option 6 is ruled out }
W B W
W W B - Ruled Out by B in Step 2.
Step 3: C knows that B wasnt able to answer , the only case where he wont be able to answer is when C is wearing a Black. Hence the answer ... C is wearing Black
Person C was wearing a Black Cap.
- Anonymous June 29, 2012