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

Explain how?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

Two friends were stuck in a cottage. They had nothing to do and thus they started playing cards. Suddenly the power went off and Friend 1 inverted the position of 15 cards in the normal deck of 52 cards and shuffled it. Now he asked Friend 2 to divide the cards into two piles (need not be equal) with equal number of cards facing up. The room was quite dark and Friend 2 could not see the cards. He thinks for a while and then divides the cards in two piles.

On checking, the count of cards facing up is same in both the piles. How could Friend 2 have done it ?

There was a minor accident with a doctor's son but the doctor noticed no major injury. After the treatment, the father of that doctors son is sitting with the son of the doctor without the doctor being in the room.

How can this be possible?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

What is red and smells like blue paint?

How can you make a TV, a bed, a dog, and a car liquid?

Replace the question mark with the correct number.

The centre of the third figure is empty. What digit should fit inside?