I can write cow in 13 letters.

Can You?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

What goes up but never comes down?

Which part of London exists in France as well ?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

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

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?