每日一题

Mathematics>Standard Multiple Choice

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

In 2012, a cheetah set a new record by running 100 meters in 5.95 seconds. What was the cheetah's approximate average speed during this record-breaking run, in miles per hour?(1.6 kilometers = 1 mile)

A.17 miles per hour
B.34 miles per hour
C.38 miles per hour
D.60 miles per hour

答案和解析

答案：C

解析：

Option C is correct. Since there are 1,000 meters in 1 kilometer, and 1.6 kilometers in 1 mile, 100 meters can be converted to miles as 100/1000(1.6)=0.0625 miles. Similarly, since there are 60 seconds in 1 minute, and 60 minutes in 1 hour, 5.95 seconds can be converted to hours as 5.95/(60)(60)≈0.00165 hours. Dividing the converted number of miles by the converted number of hours will give the speed in miles per hour: 0.0625/0.00165≈38 miles per hour.