SOLUTION: A dirt biker must circle a 12-mile track twice. His average speed must be 60 mph. On his first lap, he averaged 50 mph. How fast must he travel on his second lap in order to qualif
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Question 1120554: A dirt biker must circle a 12-mile track twice. His average speed must be 60 mph. On his first lap, he averaged 50 mph. How fast must he travel on his second lap in order to qualify? Answer by ikleyn(52814) (Show Source):
The time equation is
+ = .
Solve for x, where x is the speed on the second lap.
12*50*60 + 12*60*x = 24*50*x
12*50*60 = 24*50*x - 12*60*x
x = = 75.
Answer. The speed under the question is 75 mph.
Check. + = = = = = of an hour = 24 minutes.
! Correct !