An airplane flew for 2 hours with a 30 mph tailwind wind fro

An airplane flew for 2 hours with a 30 mph tailwind (wind from behind). The return flight against a 25 mph headwind took 3 hours. Find the speed of the airplane in still air.

Solution

Let speed of the plane in still air be \"p\".
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With wind DATA:
time = 2 hrs ; rate = p+30 mph ; distance = rt = 2p+60 miles
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Against wind DATA:
time = 3 hrs ; rate = p-25 mph ; distance = rt = 3p-75 miles
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Equation:
distance = distance
2p+60 = 3p-75
p = 135 mph (speed of the plane in still air)