Previous Year NEET Question- Infinite Series

• Q.1. The sum of the series $1 + 2 + 3 + … + n$ is (A) $\frac{n(n+1)}{2}$ (B) $\frac{n(n+1)(n+2)}{3}$ (C) $\frac{n(n+1)}{2}$ (D) $\frac{n(n+1)(n+2)}{6}$ [NEET 2013]

The answer is (A).

We can use the following formula to find the sum of a finite arithmetic series:

$$S_n = \frac{n(n+1)}{2}$$

In this case, $n$ is the number of terms in the series, and $a$ is the first term in the series.

In the given series, $a = 1$ and $n$ is the number of terms in the series. Therefore, the sum of the series is:

$$S_n = \frac{n(n+1)}{2}$$

• Q.2. The sum of the series $\frac{1}{2} + \frac