Principle Of Mathematical Induction Question 62
Question: The sum of n terms of $ 1+\frac{1+2}{2}+\frac{1+2+3}{3}+… $ is
Options:
A) $ \frac{m(n+3)}{4} $
B) $ \frac{(n+3)}{3} $
C) $ \frac{n(n-3)}{3} $
D) $ \frac{n(n-3)}{4} $
Correct Answer: A
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Answer:
Solution:
$ \Rightarrow \sum{\frac{n+1}{2}=\frac{1}{2}(\sum{n}+\sum{1})=\frac{1}{2}[ \frac{n(n+1)}{2}+n ]} $ $ =\frac{n(n+1)+2n}{4}=\frac{n(n+3)}{4} $
BETA
