Question 300628
A jet travels 3582 mil  against a jetstream in 6 hours and 4602 mi with the jetstream in the same amount of time. What is the rate of the jet in still air and what is the rate of the jetstream? 

let speed of jet in still air be x
speed of jetstream be y 

3582 /x-y = 6

3582 = 6x -6y

597=x-y

4602 / x+y= 6

6x+6y = 4602

x+y= 767


x-y+x+y= 597 + 767

2x=1364

x= 682 mph speed in still air

plug the value of x

682+y=767

y= 767-683

y= 83 mph whch is the speed of the stream