SOLUTION: A certain plane flying with the wind travels 540 mi in 2 hr. Later, flying against the same wind, the plane travels 690 mi in 3 hr. Find the speed of the plane in still air and th

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: A certain plane flying with the wind travels 540 mi in 2 hr. Later, flying against the same wind, the plane travels 690 mi in 3 hr. Find the speed of the plane in still air and th      Log On

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Question 325959: A certain plane flying with the wind travels 540 mi in 2 hr. Later, flying against the same wind, the plane
travels 690 mi in 3 hr. Find the speed of the plane in still air and the speed of the wind.
I must solve this problem using a system of equations.

I got these two equations which led to a solution, but it doesn't seem like it was done right. 2(x + y) = 540 & 3(x – y) = 690

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
with the wind plane travels 540 mi in 2 hr.
flying against , the plane travels 690 mi in 3 hr.
..
let speed of plane in still air be x mph
& speed of wind be y mph
..
With wind
Time taken = 540 / x+y= 2
540 =2x+2y
270=x+y........................1
..
Against wind
Time taken = 690/ x-y = 3
..
690=3x-3y
230=x-y........................2
..
Add equation 1 & 2
x+y+x-y=270+230
2x=500
x=250 mph speed of plane
..
plug the value of x in equation 1
270=250+y
y= 20 mph the speed of wind