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

Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

All of you like to eat me. I am a five-lettered word. Remove the first two and I turn into an infamous animal. Remove just the first and I become a heinous crime. Remove the first and the last and you can groove on me.

Can you guess who am I?

Find the next number in the following series:
6, 14, 26, 98, __?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

A man is surviving on an island along with his friend. They have been starving for four days for food. Suddenly, they find a fisherman. The friend goes with the fisherman in order to catch the fish (if they can find any).

The fisherman returns after some time but he is alone and has some salmon that he had prepared. When asked, the fisherman tells him that his best friend fell off the boat and drowned in the water. Starving for so long, he eats the meal while crying for his friend.

After being rescued, he goes to a diner and orders salmon. When he eats his meal, he jumps and commits suicide. Why did he do it?

You enter your friend's room. He is not in his room. Although you see that on the bed there are two dogs, five cats, two giraffes and three pigs. Also, a couple of chickens and ducks are flying in the room.

Calculate the number of legs standing on the floor.

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?