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

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Solve below popular number sequence
314 159 265 358 979 323 846 ?

John is 45 years older than his son Jacob. If you find similarities between their ages, both of their ages contain prime numbers as the digits. Also, John's age is the reverse of Jacob's age.

Can you find their ages?

I have branches, but no fruit, trunk or leaves. What am I?

A sundial has the fewest moving parts of any timepiece. Which has the most?

In a supermarket, there is an intelligent glass pane before a refrigerating unit. This glass pane allows cherries and apples through it but does not allow grapes and Orange to pass through it.

Can you identify the rule that the glass pane is following?

No matter how little or how much you use me, you change me every month. What am I?