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Question 370333: An express train travels 520 miles in the SAME AMOUNT OF TIME in which a freight train travels 320 miles. The rate of the express train is 25mph faster than the rate of the freight train. Find the rate of the express train and the rate of the freight train?
Answer by amoresroy(361)   (Show Source):
You can put this solution on YOUR website! An express train travels 520 miles in the SAME AMOUNT OF TIME in which a freight train travels 320 miles. The rate of the express train is 25mph faster than the rate of the freight train. Find the rate of the express train and the rate of the freight train?
Let e = the rate of the express train in mph
f = the rate of the freight train in mph
time = distance/speed
520/e = 320/f
e = f + 25
substitute e = f + 25 in 1st equation
520/(f+25) = 320/f
Cross multiply
520f = 320(f+25)
520f-320f = 8,000
200f = 8,000
f = 40
S0,
e = 40 + 25 = 65
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