Marcie can walk 8 miles in the same time as Frank walks 6 miles. If Marcie walks 1 mile per hour faster than Frank, then how fast does each person walk?

:

Let s = F's walking speed

then

(s+1) = M's walking speed

:

It says the times are equal; write a time equation: Time =

M's time = F's time

=

Cross multiply

8s = 6(s+1)

8s = 6s + 6

8s - 6s = 6

2s = 6

s =

s = 3 mph is F's speed

and

4 mph is M's speed

:

;

Check solutions by ensuring the times are equal:

8/4 = 2hr

6/3 = 2hr