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

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Can you fill the blank with the correct number?

6 30 870 756030 _____

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

If your uncle’s sister is not your aunt, what relation is she to you?

I have teeth but i don't bite. Who Am I ?

The more of this there is, the less you see. What is it?

What does this rebus riddle means ?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

Can you identify the hidden rebus in the image below?