2011 AMC10A 真题

2011 AMC 10A

Problem 1

A cell phone plan costs each month, plus ¢ per text message sent, plus ¢ for each minute used over hours. In January Juan sent text messages and talked for hours. How much did he have to pay?

一种手机套餐每个月有 20 美元的固定费用。此外，每条短信收取 美分，语音通话超过 5 30 小时的部分，每分钟收取 10 美分。 月份 1 Michelle 发送了 100 条短信，通话 30.5 小时。她需 要支付多少美元？

(B) $24.50 (C) $25.50 (D) $28.00 (E) $30.00

Problem 2

A small bottle of shampoo can hold 35 milliliters of shampoo, whereas a large bottle can hold 500 milliliters of shampoo. Jasmine wants to buy the minimum number of small bottles necessary to completely fill a large bottle. How many bottles must she buy?

一小瓶可以装 35 毫升洗发水，而一大瓶可以装 500 毫升洗发水。 Jasmine 想买最少数量的小 瓶洗发水来装满一大瓶。她必须买多少小瓶？

(A) 11 (B) 12 (C) 13 (D) 14 (E) 15

Problem 3

Suppose denotes the average of and , and denotes the average of , and . What is ?

假设 表示 a 和 b 的平均值， 表示 , 和 的平均值。那么 是 多少