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

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

2/3 x 3/10 = 2/10 = 1/5 spent on books

3/10 - 2/10 = 1/10 of the allowance saved