algebra
posted by Astrid .
Sean and Barry are practicing in a 30mile bike race. Sean averages 20 miles per hour and Barry averages 15 miles per hour. Howm many miles will Barry be from the finish line when Sean finishes the race?

At 20 miles per hour, Sean should finish the race in 1.5 hours.
30/20 = 1.5
After 1.5 hours, Barry should have ridden 22.5 miles, making him 7.5 miles from the finish line.
15 miles in 1 hour and 7.5 miles in 0.5 hours.