Question 65327
Freight train speed =x so the speed of the passenger train is x + 25
Time = distance/speed so
{{{325/(x+25)=200/x}}}
Multiply each side by x
{{{325x/(x+25)=200}}}
Multiply each side by (x+25)
{{{325x=200(x+25)}}}
{{{325x=200x+5000)}}}
Subtract 200x from each side
{{{125x=5000)}}}
x=5000/125
=40 mile per hour and the passenger train speed is 65 miles per hour

(A non algebra method would take the idea that the passenger train travels an extra 125 miles and is 25 miles per hour faster so the journey would take 5 hours. The speeds would therefore be 325/5 = 65 miles per hour and 200/5=40 miles per hour)