9. Two buses are leaving from different schools to carry students to a band
competition. Bus A travels 160 miles the first day, and an average of 60 miles
per hour on the second day. Bus B travels 240 miles the first day of the trip,
and an average of 50 miles per hour on the second day. After how many
hours on the second day will both buses have driven the same total number
R
of miles?