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Difficulty: EasyAverage Speed

A rescue helicopter flies 150150 miles to an offshore oil rig in 9090 minutes. The return flight to the base along the same route takes 150150 minutes due to strong headwinds. What is the helicopter's average speed in miles per hour for the entire round trip?

  1. 75Answer
  2. B
    80
  3. C
    125
  4. D
    37.5

Answer

75
The average speed for an entire trip is found by dividing the total round-trip distance (300300 miles) by the total round-trip time in hours (44 hours), which gives 7575 miles per hour.

Step-by-Step Solution

1
Calculate the total distance traveled for the round trip.
150 miles+150 miles=300 miles150 \text{ miles} + 150 \text{ miles} = 300 \text{ miles}
Average speed is based on the entire distance covered during the trip.
2
Convert the flight times from minutes to hours.
90 minutes=1.5 hours90 \text{ minutes} = 1.5 \text{ hours}, and 150 minutes=2.5 hours150 \text{ minutes} = 2.5 \text{ hours}
The question asks for the speed in miles per hour, so the time units must be converted to hours.
3
Calculate the total time elapsed for the round trip.
1.5 hours+2.5 hours=4 hours1.5 \text{ hours} + 2.5 \text{ hours} = 4 \text{ hours}
Average speed is based on the total time taken for the entire journey.
4
Divide the total distance by the total time.
300÷4=75 mph300 \div 4 = 75 \text{ mph}
The formula for average speed is Total Distance divided by Total Time.

Key Concept

Average Speed
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Average Speed

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