What is the average of all numbers between 8 and 74 which are divisible by 7?
A. 40
B. 41
C. 42
D. 43
Answer: Option C
Solution(By Examveda Team)
$$\eqalign{ & 14,\,21\,......\,70 \cr & \mathop {8 - - - - - - - 74}\limits_{{\text{Divisible by 7}}} \cr & {\text{Number of items}} = \frac{{{\text{Lat term}} - {\text{First term}}}}{{{\text{Common Difference}}}} + 1 \cr & = \frac{{70 - 14}}{7} + 1 \cr & = 9 \cr & {\text{Average of all number divisible by 7}} \cr & \Rightarrow \frac{n}{{2 \times n}}\left[ {a + l} \right] \cr & \Rightarrow \frac{{84}}{2} \cr & \Rightarrow 2 \cr} $$Related Questions on Average
A. 125 km/hr
B. 75 km/hr
C. 135 km/hr
D. 120 km/hr
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