SOLUTION: A passenger train leaves the train depot 2hours after freight train left the same depot.The freight train is traveling 20 mph slower than the passenger train.Find the rate of each

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Question 1063817: A passenger train leaves the train depot 2hours after freight train left the same depot.The freight train is traveling 20 mph slower than the passenger train.Find the rate of each train,if the passenger train overtakes the freight train in three hours.
Prove the equation of the problem.
Answer by josgarithmetic(39631) About Me  (Show Source):
You can put this solution on YOUR website!
Constant Travel Rates Rule, RT=D, to relate rate R, time T, distance D. 

                     SPEED      TIME      DISTANCE

Passengertrain        r          3          d

Freighttrain         r-20       3+2         d


The description gives enough information to know the times for both trains. Only two unknown variable to solve: Passenger train, r, and the overtake-distance, d.

system%28r%2A3=d%2C%28r-20%29%2A5=d%29--------two formulas for d.

The question only asks for r and r-20.
3r=5%28r-20%29