Question

Jack did 3/5 of the problems on his weekend homework before Sunday. On Sunday, he solved 1/3 of what was left and the last 4 problems. How many problems were assigned for the weekend?

Answer 1

15 problems were assigned for the weekend.

Explanation:

Let x denote the number of problems assigned for the weekend.

Before Sunday, he did 3/5 of the problems, so he is left with (1-3/5)x = 2/5 x of the problems.

On Sunday, he solved 1/3 of what was left of the problems, so he is left with (1 - 1/3)(2/5 x) = (2/3) * (2/5) x = 4/15 x problems.

4/15 x equals 4 because those were the last remaining problems, so we can solve for x:

`(4)/(15)x=4\\x = 4 \cdot (15)/(4) = 15`

So 15 problems were assigned for the weekend.