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

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

Can you name an animal whose killing cannot be performed without spilling your own blood?

A man is looking at a photograph of someone. His friend asks who it is. The man replies, “Brothers and sisters, I have none. But that man’s father is my father’s son.” Who was in the photograph?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

I am a five-letter word under you,
Remove the first letter and I am above you,
Remove the second as well and I am around you.

Who am I?

If you say my name, I will no longer exist. What am I?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

John and Jenni are a married couple. They have two kids, one of them is a girl. Assume safely that the probability of each gender is 1/2.
What is the probability that the other kid is also a girl?

Hint: It is not 1/2 as you would first think.

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?