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

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

18 ? 12 ? 4 ? 5 = 59

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?

What is harder to catch the faster you run?

The more of this there is, the less you see. What is it?

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?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Count the number of triangles in the picture below:

Can it be possible to build a house that has all its four walls facing towards the South?