How much money did he get from grandma?

Question

Grandma sent Johnny some money for his birthday. Johnny spent all of it in five stores. In each store, he spent $1.00 more than half of what he had when he came in.
How much money did he get from grandma?

Answer 1

Can be done backwards way..

Amount he had when he came into 5th store = $2 (since 1 dollar more than half is all he has)
Amount he had when he came into 4th store = (2+1)2 = 6 (as he spent $1 more than half in 4th store leaving $1 less than half for 5th store)

Amount he had when he came into 3th store = (6+1)2 = 14

Amount he had when he came into 2th store = (14+1)2 = 30

Amount he had when he came into 1th store = (30+1)2 = 62

Money he got from grandma = $ 62