###
**The sum of first n odd natural numbers in.**

A. 2n – 1
B. 2n + 1
C. $\mathrm{n}^{2}$
D. $\mathrm{n}^{2}$ -1
**Answer: Option C**

## Show Answer

Solution(By Apex Team)

1, 3, 5, 7, …….. are n odd numbers
Where a = 1, and d = 2
$\begin{aligned}\therefore S_n&=\frac{n}{2}[2a+(n-1)]\\
&=\frac{n}{2}[2\times1+(n-1)\times2]\\
&=\frac{n}{2}[2+2n-2]\\
&=\frac{n}{2}\times2n\\
&=n^2\end{aligned}$

## Related Questions On Progressions

### How many terms are there in 20, 25, 30 . . . . . . 140?

A. 22B. 25

C. 23

D. 24

### Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.

A. 5B. 6

C. 4

D. 3

### Find the 15th term of the sequence 20, 15, 10 . . .

A. -45B. -55

C. -50

D. 0

### The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is

A. 600B. 765

C. 640

D. 680