# Computing velocity of wind

#### WMDhamnekar

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?

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:

#### Lev888

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?

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.

#### Cervesa

let $v$ be the wind speed

$300 - v = \dfrac{5}{8}(300 + v)$

#### WMDhamnekar

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.

#### Lev888

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.