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Question

Difficulty: MediumRound Trips

A medical evacuation helicopter is dispatched from its base camp to pick up a patient at a rural hospital 120120 miles away. The pilot flies to the hospital at a steady speed of 120120 mph. Due to heavy headwinds on the way back, the helicopter's average speed for the entire round trip drops to 8080 mph. What is the helicopter's average speed, in mph, during the return flight?

Answer: 60 mph

Answer

60
By finding the total trip time (3 hours) and subtracting the outbound time (1 hour), we determine the return trip took 2 hours to cover 120 miles. Dividing the 120-mile distance by the 2 hours yields an average return speed of 60 mph.

Step-by-Step Solution

1
Calculate the total round-trip distance
240 miles
The one-way distance is 120 miles, so the full round trip is 120 + 120 = 240 miles.
2
Determine the total flight time
3 hours
Time equals total distance divided by the overall average speed (240 / 80 = 3).
3
Calculate the time taken for the outbound flight
1 hour
Time equals outbound distance divided by outbound speed (120 / 120 = 1).
4
Find the time taken for the return flight
2 hours
Return time is the total trip time minus the outbound trip time (3 - 1 = 2).
5
Calculate the average speed of the return flight
60 mph
Speed equals return distance divided by return time (120 / 2 = 60).

Key Concept

Average speed for a round trip is the total distance divided by the total time, not the arithmetic mean of the two different speeds.
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Topics

Round Trips

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