Sequence And Series Question 285
Question: After inserting $ n $ A.M.’s between 2 and 38, the sum of the resulting progression is 200. The value of $ n $ is
[MP PET 2001]
Options:
A) 10
B) 8
C) 9
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
The resulting progression will have $ n+2 $ terms with 2 as the first term and 38 as the last term. Therefore the sum of the progression $ =\frac{n+2}{2}(2+38)=20(n+2) $ . By hypothesis, $ 20(n+2)=200 $
$ \Rightarrow $ $ n=8 $ .
BETA
