SOLUTION: Warren drives his car 120 miles and has a mean of a certain speed. If the mean speed had been 3 mph more, he could have traveled 129 miles in the same length of time. What was his

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Question 918601: Warren drives his car 120 miles and has a mean of a certain speed. If the mean speed had been 3 mph more, he could have traveled 129 miles in the same length of time. What was his mean speed?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Warren drives his car 120 miles and has a mean of a certain speed.
If the mean speed had been 3 mph more, he could have traveled 129 miles in the same length of time.
What was his mean speed?
:
Let s = actual mean speed
then
(s+3) = faster speed
:
write a time equation, time = dist/speed
120%2Fs = 129%2F%28%28s%2B3%29%29
cross multiply
129s = 120(s+3)
129s = 120s + 360
129s - 120s = 360
s = 360/9
s = 40 mph is his actual speed
:
:
Check; find the actual time at each speed
120/40 = 3 hrs
129/43 = 3 hrs