Replace the question mark with the number below given a simple math problem.

What has to be broken before you can use it?

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

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

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

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

Look at the picture and find out which square is not linked with any of the other squares.

Which is the correct shadow of the bird?

Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?