posted by jennifer .
at 8:00am the smiths left a campground, driving at 48 mi/h. at 8:20am the garcias left the same camp ground and followed the same route, driving at 60 mi/h. at what time did they overtake the smith's?
How far did the Smiths drive from 8 a.m. to 8:20 a.m.; i.e., in 20 minutes?
distance = rate*time.
d = 48mi/hr * 1/3 hr = 16 miles which the Smiths had as a head start.
let x = distance driven by Garcias. time = d/r = x/60.
time for Smiths = x-16 is distance driven. time = (x-16)/48.
Set time = time or
x/60 = (x-16)/48
solve for x.
That will be the distance. Plug that into x/60=time and calculate time. Add that to 8:20 to know the final time at which both reached the same point. Post you work if you run into trouble.