SOLUTION: If Edna leaves now and drives at 30 mi/h, she can reach Athens just in time for her night class. On the other hand, if she eats a snack and leaves in 20 min, she has to drive 45 mi

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: If Edna leaves now and drives at 30 mi/h, she can reach Athens just in time for her night class. On the other hand, if she eats a snack and leaves in 20 min, she has to drive 45 mi      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 720399: If Edna leaves now and drives at 30 mi/h, she can reach Athens just in time for her night class. On the other hand, if she eats a snack and leaves in 20 min, she has to drive 45 mi/h ti make it to her class on time. How far away is Athens?
I do not even know how to set this problem up.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
If Edna leaves now and drives at 30 mi/h, she can reach Athens just in time for her night class.
On the other hand, if she eats a snack and leaves in 20 min, she has to drive 45 mi/h ti make it to her class on time.
How far away is Athens?
:
Change 20 min to 1/3 hr
:
Let d = distance to the class
:
Write a time equation
d%2F30 = d%2F45 + 1%2F3
multiply by 90 to clear the denominators
3d = 2d + 30
3d - 2d = 30
d = 30 mi to class
:
:
Check this; find the driving time at each speed
30/30 = 1 hr to get to class on time
30/45 = 2/3 hrs which allows 1/3 hr for a snack