# Thread: Ration expression word problem please help!

1. ## Ration expression word problem please help!

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

I got 500/s-20km per hour = 600/s+20km per hour, but could get no further. Please help!

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

I got 500/s-20km per hour = 600/s+20km per hour, but could get no further. Please help!
your formula is fine but
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 $100$

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