What has hands, but can’t clap?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

A girl is twice as old as her brother and half as old as her father. In 50 years, her brother will be half as old as his father. How old is the daughter now?

What is black when you buy it, red when you use it, and gray when you throw it away?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

How many triangles can you find in this given picture?

A man dies of old age on his 25 birthday. How is this possible?