What always comes into a house through the keyhole?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

If it took eight men ten hours to build a wall, how long would it take four men to build it?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?