AMC8 2016

AMC8 2016 · Q14

AMC8 2016 · Q14. It mainly tests Rates (speed), Arithmetic misc.

Karl's car uses a gallon of gas every 35 miles, and his gas tank holds 14 gallons when it is full. One day Karl started with a full tank of gas, drove 350 miles, bought 8 gallons of gas, and continued driving to his destination. When he arrived, his gas tank was half full. How many miles did Karl drive that day?

Karl的小汽车每35英里耗油1加仑，其油箱满时可装14加仑。有一天Karl从满油箱开始，开车350英里，买了8加仑油，继续开车到目的地。到达时油箱半满。那天Karl总共开了多少英里？

(A) 525 525

(B) 560 560

(D) 665 665

(E) 735 735

Answer

Correct choice: (A)

正确答案：（A）

Solution

In driving 350 miles, Karl used $350/35=10$ gallons of gas, so he had $14-10=4$ gallons left in his tank. After buying 8 more gallons, he had $4+8=12$ gallons. When he arrived at his destination, he had $14/2=7$ gallons left, so he used an additional $12-7=5$ gallons. This let him drive an additional $5\cdot 35=175$ miles, so he drove a total of $350+175=525$ miles.

行驶了 350 英里，Karl 用了 $350/35=10$ 加仑汽油，因此油箱还剩 $14-10=4$ 加仑。再加了 8 加仑后，他有 $4+8=12$ 加仑。到达目的地时，他还剩 $14/2=7$ 加仑，所以又用了 $12-7=5$ 加仑。这使他又行驶了 $5\cdot 35=175$ 英里，因此总共行驶了 $350+175=525$ 英里。

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