speed of wind word problem

Question

Trey flies a plane against a headwind for 4389 miles. The return trip with the wind took 20 hours less time. If the wind speed is 10 mph, how fast does Trey fly the plane when there is no wind?

Answer 1

Brooke,

 

Take a look at the solutions the tutors provided for the problem posted just below this one.  The method is essentially the same.

 

Let t = trip time against the headwind.  This time you must solve the following two equations in two unknowns t and v:

 

(v - 10) t = 4389

 

(v + 10) (t - 20) = 4389

 

Get t from the first equation, substitute it into the second equation and solve for v.  Then get a final value for t by substituting v back into the first equation.  Finally, test your solutions.  Make sure your t and v results satisfy both equations.