Find the average of all the numbers between 40 and 80 which are divisible by 3.	Pick one:
A) 15	B) 70	C) 20	D) 60	E) None
Sol.   Average = (42+ 45+ 48+ 51+ 54+ 57+ 60+ 63+ 66+ 69+ 72+ 75+ 78 / 13) = 780 / 5 = 60.   Answer 60
<result>D</result>
Find the average of all the numbers between 40 and 80 which are divisible by 3.