F.2 maths Inequalities 急!!!
2009-03-11 3:38 am
On a highway,car A and car B travel in an opposite direction from each other from the same starting point.The speeds of cars A and B are 75 km/h and 85 km/h respectively.How long(in minute) will it take for cars A and B to be at least 30 km apart?
回答 (1)
2009-03-11 4:27 am
✔ 最佳答案
Let x hours will it take:x(75 + 85) >= 30
x >= 30/160
x >= 3/16
So it will take 3/16hour = 60 * 3/16 =11.25minutes that two cars to be at least 30 km apart.
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