<PRE><B>Question 1079435</B>
let t be the time when the distance covered by the truck is equal to the distance covered by the car
:
10 minutes = 10/60 = (1/6) of an hour
:
the truck&#39;s rate is 60 mph, so the truck has (1/6) * 60 = 10 mile head start when the car enters the highway
:
60t + 10 = 75t
:
15t = 10
:
t = 10/15 = 2/3 of an hour
:
(2/3) * 60 minutes = 40 minutes 
:
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40 minutes later the car overtakes the truck
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:
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