Question 235973
Assuming they started from the same place @ the same time then:
516t-420t=4,680
96t=4,680
t=4,680/96
t=48.75 hours after they leave they will be 4,680 mileas apart.
Proof:
516*48.75-420*48.75=4,680
25,155-20,475=4,680
4,680=4,680