first, we can see the problem:
This is a story of four boys - Chinku, Dinku, Pinku and Tinku.
One day all of them decide to save their money in a bank. They select a
bank called "Lena Bank"
The bank's specialty is: In every month the money gets doubled.
In 2nd month, Chinku withdraws 100-Rs from bank.
In 3rd month, Dinku withdraws 100-Rs from bank.
In 4th month, Pinku withdraws 100-Rs from bank.
In 5th month, Tinku withdraws 100-Rs from bank. Then their balance in the
bank becomes zero.
How much amount had the boys put in the bank?
OK, please see the problem-solving steps: