how many laps?

Question

?Overlaps Two cyclists are competing in a 12-mile race on a quarter-mile circular track. They begin at the same time. One biker’s average speed is 24 miles per hour. The other’s average speed is 30 miles per hour. How many complete laps will the slower cyclist have left to complete after the faster cyclist finishes?

Answer 1

since each lap is 1/4 mile in length, there are 4 laps per mile.

 

driver 1 will finish the race in 0.4 hours (12 miles ÷ 30mph)

 

in 0.4 hours driver 2  will cover 9.6 miles (0.4h x 24mph)

 

since the race course is 12 miles, driver 2 will be 12 - 9.6 = 2.4 miles behind driver 1

 

2.4 miles x 4 laps/mile = 9.6 laps