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?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

I look at you, you look at me I raise my right, you raise your left. What am I?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

What is both possible and impossible at the same time?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Can you place three balls such that the equation shown in the picture holds true?

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

A man dies of old age on his 25 birthday. How is this possible?