Problem solving rational number

Question

Matt spent 3/10 of his allowance on projects, 2/5 on snacks, and 2/3 of the remainder on books.

1.What fraction of his allowance was spent on books? 

2.If he saved the rest, what fraction of his allowance did he save?

Answer 1

Matt spent 3/10 of his allowance on projects, 2/5 on snacks, and 2/3 of the remainder on books.

First we need to see how much was left for the books to take 2/3 of;

3/10 + 2/5 = 3/10 + 4/10 = 7/10

The remainder is then 3/10.

1.What fraction of his allowance was spent on books? 

2/3 of 3/10 = 2/3 * 3/10 = 6/30 = 1/5 (AKA 2/10)

2.If he saved the rest, what fraction of his allowance did he save?

3/10 Remainder - 2/10 spent on books = 1/10 went to savings.