What is the average of first 21 multiples of 7 ?
Choose the most appropriate option.
A) 70	B) 77	C) 79	D) 81	E) 82
Required average = 7(1+2+....+21) / 21   (7/21)X ( (21x22) / 2 ) (because sum of first 21 natural numbers)   = 77   77
<result>B</result>
What is the average of first 21 multiples of 7 ?