A train departed from city A to town B 180 km away at 9 in the morning.Tom

题目

A train departed from city A to town B 180 km away at 9 in the morning.Tom
arrived to the railway station late,therefore he went from A to B by car.He arrived at
B at the same time as the train.The average speed of the car was 40 km/hours more
than the average speed of the train.When started Tom from

答案

180／40＝4．5H
所以Ton迟到了火车4．5H　　其出发时间为下午1点半