Question 338976
They will be together when their distances are the same.

Let d=the circumference or length of the track.

By using d=rt, Ben's rate is d/50 and Roy's is d/40

Thus, their distances are (d/50)t and (d/40)*(t-5), respectively,

{{{(d/50)*t=(d/40)*(t-5)}}}

Divide out the d's and we have:

{{{t/50=(t-5)/40}}}

{{{t=25}}} seconds.