SOLUTION: An empty freight train traveled 60 miles from an auto assembly plant to an oil refinery. There, its tank cars were filled with petroleum products, and it returned on the same route
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Question 1154799: An empty freight train traveled 60 miles from an auto assembly plant to an oil refinery. There, its tank cars were filled with petroleum products, and it returned on the same route to the plant. The total travel time for the train was
3 1/2 hours.
If the train traveled 10 mph slower with the tank cars full, how fast did the train travel in each direction? Answer by ikleyn(52775) (Show Source):
The "time" equation is
+ = hours.
Multiply both sides by 2x*(x+10).
You will get the quadratic equation.
Reduce it to the standard form and solve by any way.
The answer is 30 mph for the slower speed and 40 mph for the faster speed.
(I solved the original equation mentally (!)
Just completed.
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Using "time" equation is a STANDARD method of solving such problems.
From this lesson, learn on how to write, how to use and how to solve a "time" equation.
