Roberto rode his bicycle for a local bike-a-thon. The bike-a-thon started at 9:00 A.M. and ended at 4:00 P.M. By 10:00 A.M., Roberto had ridden 16 miles. Except for a one-hour lunch break, Roberto rode at the same pace until 4:00 P.M.
How many miles did Roberto ride in the bike-a-thon?
