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?

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

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

What occurs twice in a week, once in a year but never in a day?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

If eleven plus two equals one, what does nine plus five equal?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

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 number comes next in this sequence:
7 8 5 5 3 4 4 _