Distance/Rate Problems

swerve wrote: ↑

Mon Jun 22, 2020 7:58 am

While driving from A-ville to B-town, Harriet drove at a constant speed of 115 kilometers per hour. Upon arriving in B-town, Harriet immediately turned and drove back to A-ville at a constant speed of 135 kilometers per hour. If the entire trip took 5 hours, how many minutes did it take Harriet to drive from A-ville to B-town?

A. 138
B. 148
C. 150
D. 162
E. 168

The OA is D

Source: Magoosh

Say the distance from A-ville to B-town is D miles.

Time taken to drive from A-ville to B-town = D/115 hours; and
Time taken to drive from B-town to A-ville = D/135 hours

=> D/115 + D/135 = 5
D/5(1/23 + 1/27) = 5
D = (25*23*27) / 50

Minutes taken by Harriet to drive from A-ville to B-town = 60*D/115 = (60*25*23*27) / (50*115) = 162 minutes

Correct answer: D

Hope this helps!

-Jay
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swerve wrote: ↑

Mon Jun 22, 2020 7:58 am

While driving from A-ville to B-town, Harriet drove at a constant speed of 115 kilometers per hour. Upon arriving in B-town, Harriet immediately turned and drove back to A-ville at a constant speed of 135 kilometers per hour. If the entire trip took 5 hours, how many minutes did it take Harriet to drive from A-ville to B-town?

A. 138
B. 148
C. 150
D. 162
E. 168

The OA is D

Solution:

We can create the equation where t is the number of hours it takes Harriet to drive from A-ville to B-town:

115t = 135(5 - t)

115t = 675 - 135t

250t = 675

t = 675/250 = 2.7

Thus, it takes 2.7 hours or 2.7 x 60 = 162 minutes for Harriet to drive from A-ville to B-town.

Answer: D