AMC10 2012 B

AMC10 2012 B · Q5

AMC10 2012 B · Q5. It mainly tests Fractions, Percent.

Anna enjoys dinner at a restaurant in Washington, D.C., where the sales tax on meals is 10%. She leaves a 15% tip on the price of her meal before the sales tax is added, and the tax is calculated on the pre-tip amount. She spends a total of $27.50 for dinner. What is the cost of her dinner without tax or tip?

Anna 在华盛顿特区的一家餐厅享用晚餐，那里的餐税为 10%。她在税前餐价上留下 15% 的小费，税是基于小费前金额计算的。她总共花了 27.50 美元吃晚饭。不含税和小费，她的晚餐费用是多少？

(A) $18 $18

(B) $20 $20

(D) $22 $22

(E) $24 $24

Answer

Correct choice: (D)

正确答案：（D）

Solution

Tax is 10% and tip is 15%, so her total cost is 100% + 10% +\n15% = 125% of her meal. Thus her meal costs $\frac{27.50}{1.25} = \$22$.

税 10% 和小费 15%，所以总费用是餐费的 100% + 10% + 15% = 125%。因此餐费为 $\frac{27.50}{1.25} = \$22$。

Topics