I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Solve the mathematical equation in the picture below.

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

What number divided by 4 is the same as that number minus 4?

I am an odd number. Take away a letter and I become even. What number am I?

I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.

If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.

Can you calculate the number of buses that the company owns at present?