<PRE><B>Question 669535</B>
 the hiking club hiked to a state park at 4 mph.
 they got a ride back to town in a truck that went 20 mph.
 If the round trip took 18 hrs, how far was it from town to the park. 
:
Let d = distance to the park and distance back to town
:
Write a time equation; time = dist/speed
:
Walk time + ride time = 18 hrs
{{{d/4}}} + {{{d/20}}} = 18
multiply by 20, cancel the denominators and you have:
5d + d = 20(18)
6d = 360
d = 360/6
d = 60 mi
:
:
See if that checks out, find the times
60/4 = 15 hrs
60/20 = 3 hrs
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tot time 18 hrs </PRE>