A train is scheduled to make a 616 mile trip in 9 hours. The train averages 60 mph during the first 240 miles and 80 mph during the next 160 miles. What must be the average speed of the train for the remainder of the trip in order for the train to arrive on schedule?
+130071 A train is scheduled to make a 616 mile trip in 9 hours. The train averages 60 mph during the first 240 miles and 80 mph during the next 160 miles. What must be the average speed of the train for the remainder of the trip in order for the train to arrive on schedule?
Time traveled in the first part = 240 / 60 = 4 hrs
Time traveled in the second part = 180 / 80 = 2 hrs
So......240 + 160 = 400 miles have been traveled
And 616 - 400 = 216 miles are left to travel
And there are 3 hours left to travel
So
Distance left to travel / Time left to travel = Rate = 216 / 3 = 72 mph
So.....the train must average 72 mph to finsih the trip on time
