A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

What do you call a fish without an eye?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

Look at the picture and find out which square is not linked with any of the other squares.

Can you spot the man between the coffee bean in the picture below ?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

I cannot talk, but I always reply when spoken to. What am I?