Who won the race?

Question

Four children had a race. At the end of the race
four statements were made:

Robert: I didn't come in first or last
David: I didn't come in last
Melissa: I was first
Bailey: I was last

You know that one, and only one, of the children
didn't tell the truth.

Who won the race?

Answer 1

Ans: David won the race
and Melissa didn't told the truth.

This question can be solved by taking different cases and goal is that given condition must be satisfied which is- only one children didn't told the truth.
In our case- Melissa didn't told the truth so he was not the first...
Bailey was last.
So Melissa occupied 2 or 3 position.
Robert is not first or last so he was also at position 2 or 3.
David didn't came last
and only 2 children can occupy 2 and 3 positions
It means David was the first

Answer 2

David came first
Mellisa was lying (If atall )