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

Explain how?

Can you find out the total number of triangles in the given figure?

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

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

What is always in front of you but can’t be seen?

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

I have branches, but no fruit, trunk or leaves. What am I?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?