A customer bought a product at the shop. However, the shopkeeper increased the price of the product by 15% so that the customer could not buy the required amount of the product. The customer managed to buy only 60% of the required amount. What is the difference in the amount of money that the customer paid for the second purchase compared to the first purchase? Choose the correct choice.
A) 27%  B) 29%  C) 31%  D) 33%  E) 35%
Let x be the amount of money paid for the first purchase.   The second time, the customer paid 0.6(1.15x)=0.69x.   The difference is 31%.   The answer is 31%.
<result>C</result>
A customer bought a product at the shop. However, the shopkeeper increased the price of the product by 15% so that the customer could not buy the required amount of the product. The customer managed to buy only 60% of the required amount. What is the difference in the amount of money that the customer paid for the second purchase compared to the first purchase?