When she was just learning to skate, it took her a long time before she could skate for long periods of time.
· On her first day, she skated just 5 minutes.
· On her second day, she skated for 10 minutes.
· The third day she skated for 15 minutes
Every day, she skated for 5 additional minutes. How many minutes did she skate on the 7th day?