What is the average of the first six (positive) odd number each of which is divisible by 7?

A. 42

B. 43

C. 47

D. 49

Show Answer

Answer-A
Solution-

Solution(By Apex Team)

According to the question, First six odd numbers which are divisible by ‘7’ 7, 21, 35, 49, 63, 77 difference in each value is 14 $\begin{array}{l}\text{ Sn }=\frac{n}{2}[2a+(n-1)d]\\ \text{ Sn }=\frac{6}{2}[2\times7+(6-1)\times14]\\ \text{ Sn }=3(14+70)\\ \text{ Sn }=252\\ \therefore\text{ Average }=\Large\frac{252}{6}\\ =42\end{array}$