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

Before Mount Everest was discovered, what was the highest mountain in the world?

You need to remove two matchsticks to make the below equation true. Can you do it ?

Can you place six X (crosses) in below board without making three in a row in any way ?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

What can you deduce from the following BrainBat?

CRY
LMKI

A Car is crossing a bridge 2 miles long. The bridge can only hold 10000 lbs, which is the exact weight of the car. The Car makes it half way across the bridge and stops. A bird lands on the car. Does the bridge collapse? Explain.

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?