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Rob made a trip to the recycling plant and back. The trip there took 5 hours and the trip back took 4 hours. He averaged 25 mph on the return trip. Find the average speed of the trip there.

A) 20 mph
B) 22 mph
C) 24 mph
D) 26 mph

1 Answer

4 votes

Final answer:

The average speed of the trip there is 25 mph.

Step-by-step explanation:

To find the average speed of the trip there, we can use the formula:
Average speed = Total distance / Total time

Since the trip there took 5 hours and the trip back took 4 hours, the total time for the round trip is 5 + 4 = 9 hours.

Let's assume the distance to the recycling plant is 'D'. Since the return trip was at an average speed of 25 mph, the distance back is 25 * 4 = 100 miles.

Therefore, the total distance for the round trip is D + 100.

Using the formula, the average speed of the round trip is:
Average speed = (D + 100) / 9

We want to find the average speed for the trip there, so we can set up the equation:
(D + 100) / 9 = (D) / 5

Cross-multiplying and simplifying the equation, we get:
5D + 500 = 9D

Subtracting 5D from both sides, we get:
500 = 4D

Dividing both sides by 4, we get:
D = 125

Therefore, the average speed of the trip there is:
Average speed = D / 5 = 125 / 5 = 25 mph

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