Complete the table series riddle by finding the number that can replace "??".

I went to the bookshop and spent one-half of the money that was in my purse.

When I came out, I found that I had as many cents as I had dollars and half as many dollars as I had cents when I went in. Find the money in my purse when I entered the store.

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

A Miser man decided to go on a vacation for a month. He goes to the bank and asks for a trip loan of $500. The bank officer asks the man that the loan can only be approved when he mortgage some valuable thing at the bank. Miser man mortgages his only car whose worth was a whopping $80000. The Bank officer laughed at him and approve the loan instantly. After vacation when the miser man returns, the bank officer asked him "Are you an idiot, why is your mortgage such an expensive car for such a short loan?".

Miser man replied with some reason and the bank officer agreed that the miser man is actually not an idiot.

What did miser man reply to the bank loan officer?.

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?