Jay Flew his airplane 500km against the wind in the same time it took him to fly 600km with the wind. The speed of the wind was 20km/h. What was the average speed of the airplane?

I use S as the speed of the airplane

2. Originally Posted by Skdch
Jay Flew his airplane 500km against the wind in the same time it took him to fly 600km with the wind. The speed of the wind was 20km/h. What was the average speed of the airplane?

I use S as the speed of the airplane

will change your variable s to R since

$Rate = \frac{Time}{Distance}$

$\frac{500}{R-20} = \frac{600}{R+20}$

cross multiply

$600(R-25) = 500(R+25)$

distribute

$600R-600(25) = 500R + 500(25)$

collect like terms and combine

$100R = 600(25) + 500(25)$

divide all terms by $100$

$R = (6)(25) + 5(25) = 375km/h$