Mai spends 7 3/5 hours in school each day. Her lunch period is 1/2 hour long, and she spends a total of 7/10 hour switching rooms between classes. The rest of
her day is spent in 6 classes that are all the same length. How long is each class?
A) 1 1/15
B) 1 3/20
C) 1 11/60
D) 1 4/15