Question 310693
Rate*Time=Distance
Freight train is train 1, passenger train is train 2.
{{{R1*T1=D}}}
{{{R2*T2=D}}}
Both go to the same destination, travel the same distance.
{{{R2=18+R1}}}
Train 2 is 18 mph faster than Train 1.
{{{T1=4.2}}}
{{{T2=3}}}
Train 2 takes 3 hours, train 1 1.2 hours longer. 
{{{R1*4.2=(18+R1)3}}}
{{{4.2R1=54+3R1}}}
{{{1.2R1=54}}}
{{{R1=45}}}mph
{{{R2=45+18=63}}} mph