against the wind a commercial airline in south america flew 952 miles in 4 hours. with tailwind the return trip took 3.5 hours. What was the speed of the plan in still air
Speed multiplied by time gives distance.
Against the wind:
4(s-w) = 952
(s-w) = 952/4 = 238 mph
With the wind:
3.5(s+w) = 952
(s+w) = 952/3.5 = 272 mph
We can eliminate the wind component by adding the two equations.
s - w = 238
s + w = 272
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2s = 510
2s = 510 mph
s = 510 mph / 2
s = 255 mph