A B747 flies 4 hours west with a 60mph tailwind returning against the wind takes 5 hours find the airspeed of the plane?

Answer 1

Call the airspeed 'A'.

Ground-speed with the wind is (A+60), and distance covered in 4 hours is 4(A+60).

Ground-speed against the wind is (A-60), and distance covered in 5 hours is 5(A-60).

You say that the distances are equal, so

4(A+60) = 5(A-60)

Clear parentheses:

4A + 240 = 5A - 300

Add 300 to each side:

4A + 540 = 5A

Subtract 4A from each side:

540 = A

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Check:

With the wind: (540+60) = 600 mph, = 2400 miles in 4 hours.

Against the wind: (540-60) = 480 mph, = 2400 miles in 5 hours.