2017年9月5日SAT官方每日一题---数学.

　　为了同学们能够更好的复习SAT考试并加强习题锻炼，澳际留学小编每天会给大家整理一到SAT官网每日一题。今天，给小主们准备的是SAT数学真题，话不多说，赶紧看看吧。希望每天的坚持可以对同学们有所帮助。

　　Read the following SAT test question and then click on a button to select your answer.

　　Lisa gives her little brother Sam a 15-second (sec) head start in a 300-meter (m) race. During the race, Sam runs at an average speed of 5 m/sec and Lisa runs at an average speed of 8m/sec, not including the head start. Which of the following best approximates the number of seconds that had passed when Lisa caught up to Sam?

　　A.5

　　B.25

　　C.40

　　D.55

　　答案：B

　　解析：

　　Choice B is correct. Let t represent the time, in seconds, that Sam spends running, let d represent the distance run, and let r represent the rate at which Sam is moving.

　　Then, since d = rt, 5t represents the total distance, in meters, Sam runs in t seconds.

　　Since Lisa gives her little brother a 15-second head start, it follows that she runs for t-15 seconds at a rate of 8m/sec.

　　So, 8(t-15) represents the total distance, in meters, Lisa runs in t-15 seconds.

　　以上就是澳际留学小编今天给大家整理的2016年9月sat真题每日一练之数学真题，与大家共享，大家好才是真的好嘛。澳际留学小编希望每天坚持提供一道试题可以帮助同学们顺利通过考试。出国留学，澳际教育一直在!