<PRE><B>Question 161239</B>
they ride at an average of 8 mph on a route that is 4 miles less than the route on the return. They travel 7 mph on the return trip. If it takes them one hour longer to return than to go, how much total time do they spend riding their bicycles?
:
Let t = travel time on outbound trip
then
(t+1) = travel time on the return trip
:
Write a distance equation: Dist = speed * time
:
Out bound dist + 4 mi = return dist
8t + 4 = 7(t+1)
8t + 4 = 7t + 7
8t - 7t = 7 - 4
t = 3 hrs
then the return trip time:
3 + 1 = 4 hrs
:
Total time in the bikes: 4 + 3 = 7 hrs
:
:
Check solution by finding the dist:
out: 3*8 = 24 mi
back: 4*7 = 28 mi
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difference = 4 mi</PRE>