Question

A car traveled from Los Angeles to San Francisco in 6 hours at an average rate of x miles per hour. If the car returned along the same route at an average rate of y miles per hour, how long did it take for the car to make the entire round trip, in minutes?

A. (6 + 6x/y)*60
B. (6 + 6y/x)*60
C. 30(x + y)
D. 10(x + y)
E. (x + y)/360

Answer 1

A

Explanation:

What we need to know simply is the time taken for both trips. We know the car spent 6 hours on the first leg, that is settled.

What we do not know is the time spent on the second leg. To get the time spent on the second leg of the journey, we only need to get the total distance divided by the speed.

We can get the distance using the first part of the question. The time is 6 hours and the speed is x miles per hour, the total distance is this 6x miles.

Now we need to know the time spent on the second leg of the journey. We know that the distance is the same. Hence the time spent is 6x/y where y is the speed for the second leg and 6x is the length of each leg

Now the total time spent is thus (6x/y +6) hours. We need to however convert this to minutes. We do this by multiplying by 60

(6x/y + 6) * 60