Answer:
105 seconds
Explanation:
We can use the relation ...
distance = speed ยท time
to write equations for the distance each girl travels as a function of time t since Jillian started.
Jillian's distance = (6 ft/s)(t)
Samantha's distance = (7 ft/s)(t -15) . . . . Samantha starts 15 seconds after the clock starts running
These distances are the same when ...
6t = 7(t -15)
6t = 7t -105 . . . . eliminate parentheses
105 = t . . . . . . . . add 105-6t
Jillian had been walking 105 seconds when the two girls met.