I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

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

Explain how?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

A man is found unconscious in front of a store at two in the morning. His head is bleeding and there’s a brick laying next to him. When the police arrive, they carry the man to jail. Why did they arrest him?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

When 99 is considered higher than 100?

Make a sentence consisting of three words that have the whole alphabet.

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).