# Against the wind a small plane flew 210 miles in 1 hour and 10 minutes. The return trip took only 50 minutes. How do you determine the speed of the plane?

##### 2 Answers

Speed of the plane

#### Explanation:

If

and

We are told

[1]

[2]

Adding [1] and [2]

[3]

[4]

[5]

[6]

I found

#### Explanation:

Call

Against the wind you have:

where I used the fact that velocity=distance/time and changed time in minutes.

When the wind is in the same direction you get:

From the first equation:

and using this into: