Question

As a trains engineer, Erin guided the train on a 64 mile run which took 1.7 hours. She then stopped on a side rail to let a second train pass. She then continued another 80 miles, which took 1.9 hours what was the trains average speed for the entire run? There are no answer choices!

Answer 1

To find the rate (or speed) of an object you use the equation

Rate = Distance x Time or 

d = rt          So, just fill in the equation with the first set of numbers.
64 = r(1.7)    Then divide.
r ≈ 37.65

Then, find the second speed.
d = rt
80 = r(1.9)    And divide.
r ≈ 42. 11

Since you need to find the average speed just find the average of the two speeds. So

(42.11 + 37.65) / 2

79.76 / 2

39.88

So the average speed of the train was about 39.9 miles per hour.