In a paint factory, an old conveyer line has already filled 38 barrels of paint, and is filling more at a rate of 7 barrels per hour. The company just got a newer line that can fill 8 barrels per hour, but they are just starting so there aren't any filled barrels yet. In a little while, the two lines will have filled an equal number of barrels with each line being at 304 total barrels. How long will that take?