Question 178340
let x=speed of the freight train
12+x=speed of the passenger train

the speed is equal to distance/time

and time is equal to distance/speed..

the time for the passenger train is equal to the time of the freight train....
{{{(12+x)/400=x/320}}}
simplifying,4(12+x)=5x
x=48miles-->speed of the freight train
12+x=60miles-->speed of the passenger train
^^