3 Answers | Add Yours
Suppose x is the speed of the airplane.
We also need to know that d=rt so `t=d/r`
So the rate with the wind is x+20, and the rate against is x-20 so using the above formula for time we have
` 600/(x+20)=500/(x-20)` cross multiplying we get
600(x-20) = 500(x+20) distributing
600x - 12000 = 500x + 10000 Subtracting 500x and adding 12000 gives us
100x = 22000 solving for x
x = 220km/hr our answer, which is a reasonable rate for a plane.
We could check,
time with the wind = 600/(220+20) = 600/240 = 2.5 hours
time against the wind = 500/(220-20) = 500/200 = 2.5 hours
So the answer is 220km/hr
Thanks for the help!!
I'm pretty sure all you have to do is add 600 and 500 to get 1,100 and then divide that by 20 and your answer would be 55 km/h.
We’ve answered 319,833 questions. We can answer yours, too.Ask a question