<PRE><B>Question 860309</B>
person is planning a driving trip. part of her trip will be along major highways and part will be along country roads and city streets. speed limit on highways is 100/km/hr while limit on other roads is 60 km/hr. Total time he wants to spend driving is 12 hours and he has to travel 850 km. how much time should he plan to spend on each type of road.
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100x + 60(12-x) = 850 km
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100x + 720 - 60x = 850
40x = 130
x = 13/4 = 3 1/4 = 3 hr 15 min(time on major highways)
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12-x = 48/4-13/4 = 35/4 = 8 hr 45 min (time on other roads)
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Cheers,
Stan H.
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