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

Explain how?

Three people enter a room and have a green or blue hat placed on their heads. They cannot see their own hat but can see the other hats.
The colour of each hat is purely random. They could all be green, blue, or any combination of green and blue.
They need to guess their own hat colour by writing it on a piece of paper, or they can write 'pass'.
They cannot communicate with each other in any way once the game starts. But they can have a strategy meeting before the game.
If at least one of them guesses correctly they win $10,000 each, but if anyone guesses incorrectly they all get nothing.
What is the best strategy?

My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

What can go up a chimney down, but can’t go down a chimney up?

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?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?

In the image given, you can find several triangles. Can you count them all?

How can you write nineteen in a manner that if we take out one, it becomes twenty?