Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

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

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

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

What is the riddle which can be asked all day with a different correct answer each time.

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

Which part of London exists in France as well ?

As shown in the picture below, we can see a boy hanging on the tree branch to save his life. There are various ways in which he can die like1. A snake hanging toward the right waiting to bite the boy.2. A roaring Lion near the tree.3. Two crocodiles are ready to attack if the boy reaches near water. The tree is chopped to some extent, so can fall as if he moves a lot. Can you give this boy an escape plan?

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?