Brainteaser Answer 9

The Lie Detector Test.

Answer 9: Tom is the thief!

Here is the question again: “During lunch, 5 of Mr. Bryant’s students visit the supermarket. One of the 5, stole an apple.

When questioned…

Jim said: it was Hank or Tom. Hank said: neither Eddie or I did it. Tom Said: you’re both lying. Don said: no one of them is lying, the other is speaking the truth.
Eddie said: no Don, that’s not true.

When the shop owner asked Mr. Bryant, he said that three of the boys are always truthful, but two lie all the time.

So – who stole the apple?”

Let’s work it out.

  • Don and Eddie contradict each other which means one of them must be a liar.
  • One of the remaining boys must also be lying (there are 2 liars).
  • Tom has said ‘you’re both lying’ about the two other remaining boys (Jim and Hank), but there can only be one liar, so it must be him.
  • Jim and Hank are both telling the truth so it can’t be Eddie or Hank who stole the apple.
  • Tom must have stolen the apple.

(I was suspicious about Jim at first, but if you read carefully, Jim said it was Hank OR Tom – so he’s not actually contradicting Hank’s words).

Jim, Hank and Eddie are telling the truth. Don and Tom are the liars.