A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

What work can one never finish?

You can hear me, but you can't touch or see me.

What am I?

Spot 5 differences in two Christmas tree below:

Find the next number in the following series:
6, 14, 26, 98, __?

How many Watermelons are there in the below picture?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Which tank will fill first?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?