A customer bought a product at the shop. However, the shopkeeper increased the price of the product by 10% so that the customer could not buy the required amount of the product. The customer managed to buy only 90% 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 option: A) 5% B) 4% C) 3% D) 2% E) 1%
Let x be the amount of money paid for the first purchase.   The second time, the customer paid 0.9(1.1x)=0.99x.   The difference is 1%.   The answer is 1%.
<result>E</result>
A customer bought a product at the shop. However, the shopkeeper increased the price of the product by 10% so that the customer could not buy the required amount of the product. The customer managed to buy only 90% 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?