<PRE><B>Question 141559</B>
How do I solve?
:
Let x = speed going
then
2x = return speed
:
A person traveled 120 miles in one direction. The return trip was accomplished at double the speed and took three hours less time. Find the speed going.
;
Write a time equation: Time = dist/speed
:
Going time = return time + 3 hrs
{{{120/x}}} = {{{120/(2x)}}} + 3
Multiply equation by 2x to get rid of the denominator:
2(120) = 120 + 3(2x)
:
240 = 120 + 6x
:
240 - 120 = 6x
:
120 = 6x
x = {{{120/6}}}
x = 20 mph is the go speed
:
:
Check solution by finding the times
120/20 = 6 hrs
120/40 = 3 hrs
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differ = 3 hrs</PRE>