SOLUTION: The speed of a passenger train is 18 mph faster than the speed of a freight train.The passenger train travels 300 miles in the same time it takes the freight train to travel 210 m

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The speed of a passenger train is 18 mph faster than the speed of a freight train.The passenger train travels 300 miles in the same time it takes the freight train to travel 210 m      Log On


   

Question 319878: The speed of a passenger train is 18 mph faster than the speed of a freight train.The passenger train travels 300 miles in the same time it takes the freight train to travel 210 miles. Find the speed of each train. What is the speed of the passenger train? What is the speed of the freight train? Please help me with this. Thank you.
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
D=RT
300=(R+18)T OR T=300/(R+18)
210=RT OR T=210/R
300/(R+18)=210/R CROSS MULTIPLY.
300R=210(R+18)
300R=210R+3,780
300R-210R=3,780
90R=3,780
R=3,780/90
R=42 MPH. FOR THE FREIGHT TRAIN
42+18=60 MPH. FOR THE PASSENGER TRAIN.
PROOF:
300/60=210/42
5=5 TIME OF THE TRIPS.