On a road trip, Sara's brother drove 47.5% of the trip, and Sara drove 80% of the remainder. If Sara drove for 4 hours and 12 minutes, how long was the road trip?

80 percent of 52.5 percent of the trip is 42 percent

therefore, 4 hours and 12 min (or 252 min) is 42 percent of the trip

so

252/.42 = x/1

x = 600 min

the whole trip was 10 hours