Two fathers and Two sons | funny puzzles

Two fathers and their sons (one of each father) want to a pond for fishing and each of them caught one fish and put the fishes on a basket. But when they returned, the basket had only three fishes. WHY? (there is nothing happened in the basket. Also all the fishes are taken to the basket!)

.

.

..

.

.

.

..

.

.

.

.

..

.

.

..

.

.

.

.

..

.

.

.

.

(hint: the answer is in the first sentence (Two fathers and their......on a basket ))

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

answer is in the relationship between them.

The people who went to the pond were a grandfather, a father and a son. (there are 2 fathers and 2 sons also!)