The numbers 3,5,7, a, and b have an average (arithmetic mean) of 15 . What is the average of a and b ?
Answer Choices
A. 0
B. 15
C. 30
D. 45
E. 60
The numbers 3,5,7, a, and b have an average (arithmetic mean) of 15 . What is the average of a and b ?
Answer Choices
A. 0
B. 15
C. 30
D. 45
E. 60