Question

一名司机以每小时 $60$ 英里的速度行驶 $2$ 小时，在此期间她的汽车每加仑汽油可行驶 $30$ 英里。她每英里获得 $\$0.50$ 报酬，唯一开销是每加仑 $\$2.00$ 的汽油。扣除这项开销后，她每小时的净报酬是多少美元？

A driver travels for $2$ hours at $60$ miles per hour, during which her car gets $30$ miles per gallon of gasoline. She is paid $\$0.50$ per mile, and her only expense is gasoline at $\$2.00$ per gallon. What is her net rate of pay, in dollars per hour, after this expense?

$20$

$22$

$24$

$25$

$26$

答案：E

知识点：速率单位换算

难度评级：1130

小提示：

$2$ 小时内她行驶 $120$ 英里；求出这段距离的报酬和汽油费用

In $2$ hours she drives $120$ miles; find her pay and her gasoline cost for that distance

大提示：

用净收入除以 $2$ 小时，得到每小时的报酬

Divide the net earnings by the $2$ hours to get the rate per hour

解答：

$2$ 小时内她行驶 $120$ 英里，收入为 $120 \cdot \$0.50 = \$60$ 。

她用掉 $120 \div 30 = 4$ 加仑汽油，花费 $4 \cdot \$2.00 = \$8$ 。

净收入为 $\$60 - \$8 = \$52$ ，因此每小时为 $\$52 \div 2 = \$26$ 。

因此，正确答案是 E。

In $2$ hours she drives $120$ miles, earning $120 \cdot \$0.50 = \$60.$

She uses $120 \div 30 = 4$ gallons, costing $4 \cdot \$2.00 = \$8.$

Her net earnings are $\$60 - \$8 = \$52,$ so her rate is $\$52 \div 2 = \$26$ per hour.

Thus, E is the correct answer.

2020 AMC 12A 第 3 题

答案：E

难度评级：1130

小提示：

大提示：

解答：

其他年份的第 3 题