A car travels from Town A to Town B at an average speed of

[BTGmoderatorLU]

Source: Manhattan Prep

A car travels from Town A to Town B at an average speed of 40 miles per hour and returns immediately along the same route at an average speed of 50 miles per hour. What is the average speed in miles per hour for the round-trip?

A. \(45\frac{4}{9}\)mph

B. \(44\)mph

C. \(45\)mph

D. \(44\frac{4}{9}\)mph

E. \(44\frac{1}{9}\)mph

The OA is D

[Scott@TargetTestPrep]

Source: Manhattan Prep

A car travels from Town A to Town B at an average speed of 40 miles per hour and returns immediately along the same route at an average speed of 50 miles per hour. What is the average speed in miles per hour for the round-trip?

A. \(45\frac{4}{9}\)mph

B. \(44\)mph

C. \(45\)mph

D. \(44\frac{4}{9}\)mph

E. \(44\frac{1}{9}\)mph

The OA is D

We can let the distance each way = 200 and use the formula: average rate = total distance/total time:

average rate = (200 + 200)/(200/40 + 200/50)

average rate = 400/9 = 44 4/9 mph

Answer: D