A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

Jessica is telling her friends this story and asks them to guess if it’s the truth or a lie: “There was a man sitting in a house at night that had no lights on at all. There was no lamp, no candle, and no other source of light. Yet, he sat in the house and read his book happily.” Her friends say she’s lying, but Jessica corrects them and says she’s telling the truth. Jessica’s story is true—but how?

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

When is the top of a mountain similar to a savings account?

Prove that twice of ten is the same as twice of eleven.

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

He loves to dance, twist and prance, he shakes his tail, and as a way he sails, wingless he flies into the sky. What is he?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?