Name a key which is hardest to turn.

Can you count the number of matches in the picture below ?

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

Which English verb becomes past tense just by rearranging the letters?

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.

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

There is a movie name hidden in the picture that is attached with this question. Can you find out which movie is it?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?