The world record for cycling a stretch of 20 kilometers is 26 minutes. This corresponds to an average speed of, approximately,
(A) 29 mph
(B) 46 mph
(C) 32 mph
(D) None of these
2 answers
20 km / 26 minutes = average speed of 10/13 km per minute. 1 kilometer is approximately 0.621 miles, so 10 kilometers is 6.21 miles. So then, the average speed is 6.21/13 miles per minute. There are 60 minutes per hour, so then the average speed in miles per hour is 60 * 6.21 / 13 = about 28.66 miles per hour. Thus, the answer is (A).
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