Hana sold 4/7 of her collection for $28, so 1/7 of her collection represents: 28/4 = $<<28/4=7>>7.

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

# Answer

49
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Hana sold 4/7 of her stamp collection for $28. How much would she have earned from selling the entire collection?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
49
Hana sold 4/7 of her stamp collection for $28. How much would she have earned from selling the entire collection?
train