SOLUTION: A woman drives 10 miles, then increases her speed by 10 miles per hour and drives 25 miles. Find the original speed if she drove for 45 minutes.

Algebra ->  Inequalities -> SOLUTION: A woman drives 10 miles, then increases her speed by 10 miles per hour and drives 25 miles. Find the original speed if she drove for 45 minutes.       Log On


   



Question 1009207: A woman drives 10 miles, then increases her speed by 10 miles per hour and drives 25 miles. Find the original speed if she drove for 45 minutes.
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Call her original speed, r.
The time she drove was t.
rt = 10
During the second leg, her rate was r + 10 and her time was 3/4 - t.
Here (r + 10)(3/4 - t) = 25
The solving of this takes quite a while and too many steps for this place, but it turns out that
t = 1/4 hour and
r = 40 mph