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 clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

Three playing cards in a row. Can you name them with these clues? There is a two to the right of a king. A diamond will be found to the left of a spade. An ace is to the left of a heart. A heart is to the left of a spade. Now, identify all three cards.

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

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Find the missing number in the sequence below:

John is found dead in a bare field. Nobody killed John,
John did not commit suicide.

Inspector Jacob found a bag just a few meters away from John which could save his life. What was in the bag?

Why is the Hole below a Lock?

Which alphabet is a part of our body?