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

Explain how?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

How can one talk without saying a single word?

You order chicken wings at KFC in the boxes of 6, 9 and 20. What is the largest number of wings that you cannot obtain by buying in any combination of the boxes?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?