Libby drive to work takes one hour. If she increases her average speed at 10 mph, The trip takes 3/4 hour. Find the distance she Drive to work.

Question

Math 

Answer 1

distance = rate*time

 

d = r(1)

d = (r+10)(0.75)

 

Since the distance is the same:

r = 0.75(r+10)

r = 0.75r + 7.5

0.25r = 7.5

r = 30 mph

 

Distance to work = r(1 hour) = 30 miles

 

Check:  d = (r+10)(0.75)

           30 = 40(0.75)

           30 = 30

Answer checks as correct