A train averages a speed of 90 miles per hour across the plains and 37.5 miles per hour through the mountains. if a trip of 300 miles took 3 hours and 48 minutes, how much of it was through the mountains?

Question

Mathematics

Karla Crosby

7 September, 17:25

A train averages a speed of 90 miles per hour across the plains and 37.5 miles per hour through the mountains. if a trip of 300 miles took 3 hours and 48 minutes, how much of it was through the mountains?

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Julianna Potts · Answer 1

This is a tough one. What we are looking for is how long (how much time) was spent in the mountains. So we are looking for t, time. 3 hours 48 minutes is 3.8 hours. Both have to be in terms of one or the other, you cant have unknown mountain time and plain time, so let's say that mountain time is t. That means that plain time is 3.8-t. Multiply the rates times the times for each and add them together and set them equal to the total distance. 90 (3.8-t) + 37.5t=300. Solve for t. The time spent in the mountains was 48 minutes