Macy is tutoring students in mathematics during her summer break. She charges $20 for a 30 minute session and $35 for an hour. The graph shows the number of 30 minute and 1 hour sessions she needs to have in order to make $280.

During her first week of tutoring, she only has 1 hour sessions, but makes exactly $280. How many tutoring sessions did Macy have during the first week?