The sum of the first 35 terms of the series 1/2+1/3-1/4-1/2-1/3+1/4+1/2+1/3-1/4 ….. is : · ABC26GN1075
Subject: General Aptitude · Chapter: Simplification
The sum of the first 35 terms of the series $\frac{1}{2}+\frac{1}{3}-\frac{1}{4}-\frac{1}{2}-\frac{1}{3}+\frac{1}{4}+\frac{1}{2}+\frac{1}{3}-\frac{1}{4} \ldots .$. is :
(a)$-\frac{1}{2}$
(b)$-\frac{1}{4}$
(c)$\frac{1}{4}$
(d)None of these
Answer
Answer (as printed): B
Explanation
Clearly, sum of first 6 terms is zero. So, sum of first 30 terms $=0$. $$\therefore \quad \text { Required sum }=\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}-\frac{1}{2}-\frac{1}{3}\right)=-\frac{1}{4} .$$
Explanation as extracted from the printed page; notation may be imperfect.