Help with math problem

Question

mr reeves spent 3/8 of his money on a new book, if the book cost $15, how much money did he have at first?

Answer 1

spent 3/8 of M = 15

3M/8 = 15

3M = 8(15) = 120

M = 120/3 = 40

Mr Reeves originally had Money = $40

he spent 3/8 = 3/8 x 40 = $15 spent on a book