Edgar uses his cell phone all the time, even though it's more expensive between
8 a.m. and 6 p.m. The daytime rate costs 10¢ per minute between 8 a.m. and 6
p.m., while it is 3¢ per minute all other times. If Edgar spent 60 minutes on the
phone at night and 60 minutes during the day, how much would he owe?