Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

What has 13 hearts but no other organs?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

The dirtier I get, the whiter I look. Who am I?

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

I shave every day, but my beard stays the same. What am I?

Using eight eights and addition only, can you make 1000?

What runs around the whole yard without moving?