From the sale of sleeping bags, a retailer made a gross profit of 13% of the wholesale cost. If each sleeping bag was sold for $28, what was the wholesale cost per bag?
Choices.
A) 3.0
B) 3.36
C) 24.78
D) 25.0
E) 31.36

Rationale: "cost price * 1.13 = selling price - - > cost price * 1.13 = $ 28 - - > cost price = $ 24.78 . answer : c ."
Answer: C