You've taken several TEAS practice exams. You've earned a 56%, then a 71%, then a 67%, then an 80%. On your final practice exam, you earned an 87%. What is your average score of the last three exams?

A.) 64% B.) 87% C.) 72% D.) 78%

How is the answer D? Please explain how the correct is answer 78%. 78% is the correct answer I just need to know how it was solved to get this answer