Question 83077
600/(R+20)=360/R NOW WE CROSS MULTIPLY
360(R+20)=600R
360R+7200=600R
360R-600R=-7200
-240R=-7200
R=-7200/-240
R=30 MPH FOR THE FREIGHT TRAIN.
30+20=50 FOR THE EXPRESS TRAIN.
PROOF
600/50=360/30
12=12