David drove to work at an average (arithmetic mean) speed of

[BTGmoderatorDC]

David drove to work at an average (arithmetic mean) speed of 45 miles per hour. After work, David drove home at an average speed of 60 miles per hour. If David spent a total of 2 hours commuting to and from work, how many miles does David drive to work?

A. 48
B. 256/5
C. 360/7
D. 105/2
E. 160/3

OA C

Source: Magoosh

[Scott@TargetTestPrep]

David drove to work at an average (arithmetic mean) speed of 45 miles per hour. After work, David drove home at an average speed of 60 miles per hour. If David spent a total of 2 hours commuting to and from work, how many miles does David drive to work?

A. 48
B. 256/5
C. 360/7
D. 105/2
E. 160/3

OA C

Source: Magoosh

We can let d = the distance each way and create the equation for time:

d/45 + d/60 = 2

Multiplying by 180, we have:

4d + 3d = 360

7d = 360

d = 360/7

Answer: C

[swerve]

Time = Distance / Speed

Assuming distance be x

\(\frac{x}{45}+\frac{x}{60}=2\) hours

\(\frac{7x}{180}=2\,\,\Rightarrow\,\, x = \frac{360}{7}\)

Hence, __C__ is the correct option.