Thursday, November 30, 2023

# Brain Teaser – May 28

Dr. Johnson decided to check if his physician assistant Anna is smart enough. He prepared three envelopes and put a cheque for \$100 in one of the three envelopes.

On the first envelope, he wrote â€śThis envelope does not have the chequeâ€ť, on the second envelope he wrote â€śThis envelope has the chequeâ€ť, and on the third one he wrote, â€śThe second envelope does not have the chequeâ€ť.

Then he told Anna that if she wants to get the cheque, she needs to guess which envelope contains the cheque, without touching the envelopes, just by reading the writings on the envelopes.

He also said that only one writing was true and two others were false.

Which envelope does Anna need to pick up to get the cheque?

Anna needs to pick up the first envelope.

If the statement on the second envelope is true (which means that the second envelope contains the cheque), then the statements on the first and third envelopes are false.

If the statement on the first envelope is false then the first envelope contains the cheque, but we have assumed that the second envelope contains the cheque, so we get a contradiction.

Therefore, the statement on the second envelope must be false which means that the second envelope does not have the cheque. Hence, the statement on the third envelope is true, and, therefore, the statement on the first envelope is false.

This means that the first envelope has the cheque.

RELATED ARTICLES

Stay Connected
10,288Fans
820Followers
249Followers
2,787Followers

### Brain Teaser

0
A policeman detained four suspects for a theft case. Alex: Hey, I...