Question

Miracle drove home from college traveling an average speed of 71.1 mph and drove back to the college the following week at an average speed of 60.9 mph. If the total round trip took 11 hours, how much time did it take Miracle to drive from home back to college? Express the time in hours and minutes. Round to the nearest mi

Answer 1

5 hours 56 minutes

Explanation:

average speed = distance/time

Let the time it took to go from college to home be t.

Then, the time from home back to college is 11 - t.

The distance is d in both directions.

Drive home from college:

71.1 = d/t

Drive from home to college:

60.9 = d/(11 - t)

d = 71.1t

d = 60.9(11 - t)

71.1t = 669.9 - 60.9t

132t = 669.9

t = 5.075

11 - t = 11 - 5.075 = 5.925

5.925 h = 5 h + 0.925 h × (60 min)/(1 h)

5.925 h = 5 h 55.5 min

Time rounds off to 5 hours 56 minutes.