A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

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

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

10+10 and 11+11 can give you the same answer.

Explain how?

What is black when you buy it, red when you use it, and gray when you throw it away?

A father told his three sons he would die soon and he needed to decide which one of them to give his property to. He said, “Go to the market and buy something large enough to fill my bedroom, but small enough to fit in your pocket. From this, I will decide which of you is the wisest and worthy enough to inherit my land.” They all went to the market, and each came back with a different item. The father told his sons to come into his bedroom one at a time and try to fill up his bedroom with their items. The first son came in and put some pieces of cloth he bought and laid them across the room, but it barely covered the floor. The second son came in and laid some hay on the floor, but there was only enough to cover half the floor. The third son came in and showed his father what he bought. He wound up getting the property. What did the third son show his father?

If eleven plus two equals one, what does nine plus five equal?

How can I get the answer 24 by only using the numbers 8,8,3,3?

You can use the main signs add, subtract multiply and divide.