Name the three-letter word that can complete the below words?

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

What do you get if you add 2 to 100 four times?

I am white when I am dirty, and black when I am clean. What am I?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Prove that twice of ten is the same as twice of eleven.

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

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?

What number do you get when you multiply all of the numbers on a telephone's number pad?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

What does this below rebus puzzle mean?