Hana sold 4/7 of her stamp collection for $28. How much would she have earned from selling the entire collection?
Stream of thoughts:
49
Hana sold 4 / 7 of her collection for $28, so 1 / 7 of her collection represents: 28 / 4 = $7.

And as a result, the entire collection represents: 7 * 7 = $49.

.

The final answer: 49