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

which number am I?

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

Our product and our sum always give the same answer. Who are we?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?