Computing velocity of wind

May 2019
50
1
Mumbai (Bombay),Maharashtra State,India
Hello,

Going against the wind, a domestic plane can travel 5/8 of the distance it can travel in one hour if it is going with the wind. If the plane can fly 300 kilometers an hour in calm air, what is the velocity of the wind?

Answer:- There are five answers given by the author to choose,

1)62.93kph.

2)96.23kph.

3) 63.92kph.

4)69.23kph.

5)Doubtful.

I think 62.93 kph is the correct answer. I computed it as follows:$300*\frac58=187.5, \frac{187.5}{300}=0.625$ So, 0.625*100=62.5 kph. But the author says it is wrong. Then what is the correct answer?

If any member knows the correct answer, he/she may reply to this multiple choice question.
 
Last edited:
Nov 2019
23
4
Boston
Hello,

Going against the wind, a domestic plane can travel 5/8 of the distance it can travel in one hour if it is going with the wind. If the plane can fly 300 kilometers an hour in calm air, what is the velocity of the wind?

Answer:- There are five answers given by the author to choose,

1)62.93kph.

2)96.23kph.

3) 63.92kph.

4)69.23kph.

5)Doubtful.

I think 62.93 kph is the correct answer. I computed it as follows:$300*\frac58=187.5, \frac{187.5}{300}=0.625$ So, 0.625*100=62.5 kph. But the author says it is wrong. Then what is the correct answer?

If any member knows the correct answer, he/she may reply to this multiple choice question.
Your answer doesn't match any of the choices. Why do you think it's 62.93?
You need to reread the problem. 5/8 relates speeds with and against the wind, it has nothing to do with 300. I would set up an equation with x being the wind velocity.
 
Dec 2014
154
119
USA
let $v$ be the wind speed

$300 - v = \dfrac{5}{8}(300 + v)$
 
May 2019
50
1
Mumbai (Bombay),Maharashtra State,India
Your answer doesn't match any of the choices. Why do you think it's 62.93?
You need to reread the problem. 5/8 relates speeds with and against the wind, it has nothing to do with 300. I would set up an equation with x being the wind velocity.
Hello,
I got the answer 69.23 kph. I computed it as follows. $x+ \frac58 x=300,so x=184.615384615.\frac58 of x=115.384615384,184.615384615-115.384615384=69.23076923$kph.
 
Nov 2019
23
4
Boston
Hello,
I got the answer 69.23 kph. I computed it as follows. $x+ \frac58 x=300,so x=184.615384615.\frac58 of x=115.384615384,184.615384615-115.384615384=69.23076923$kph.
Could you explain your equation?