You can
put this solution on YOUR website!D=RT
SEEING AS THE DISTANCES ARE EQUAL THEN
R(40/60)=(R+15)(30/60)
40R/60=(30R+450)/60 HERE WE CAN ELIMINATE THE DENOMINATORS THUS WE HAVE LEFT:
40R-30R=450
10R=450
R=450/10
R=45 MPH FOR THE DRIVE WHILE THE TRAIN'S RATE IS:
45+15=60 MPH FOR THE TRAIN.
PROOF
45(40/60)=60(30/60)
45*40=60*30
1800=1800