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 ?
"let x be the amount of money paid for the first purchase . the second time , the customer paid 0.9 ( 1.1 x ) = 0.99 x . the difference is 1 % . the answer is e ."
multiply(subtract(const_1, multiply(add(divide(10, const_100), const_1), divide(90, const_100))), const_100)