SOLUTION: A car and bus both completed a 240 mile trip. The car averaged 10 mph faster than the bus and completed the trip in 48 minutes less time then the bus. Find the average rate, in mil

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Question 830443: A car and bus both completed a 240 mile trip. The car averaged 10 mph faster than the bus and completed the trip in 48 minutes less time then the bus. Find the average rate, in miles per hour, of the bus.
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
r the speed for the bus
h the time in HOURS for the bus
48 minutes is 4%2F5 hour


________________speed_______________time_____________miles
Car_____________r+10________________h-(4/5)________240
Bus______________r___________________h_______________240

You could generalize everything and solve this all in symbols before using given values. Try this:

________________speed_______________time_____________miles
Car_____________r+v________________h-p_______________d
Bus______________r___________________h_______________d

Your equations from this begin as:
%28r%2Bv%29%28h-p%29=d and rh=d;
If you take the simpler equation as h=d%2Fr, and then start working with the car's equation, substituting for h and for rh, will allow you to get a quadratic equation, a very simple-looking one, in r. You could then use the general solution for a quadratic equation to get a formula for r.

... just remember what your given values were and what you wanted to find.