If the $n$ th term of an A.P is $2 n + 3$ , then sum of first $n$ term of the A.P is

n (n + 3)

No worries! We‘ve got your back. Try BYJU‘S free classes today!

n (n + 4)

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

n (n - 2)

No worries! We‘ve got your back. Try BYJU‘S free classes today!

n (n + 1)

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $n (n + 4)$
Here, $a_{n} = 2 n + 3$
$\Rightarrow a_{1} = 2 (1) + 3 = 5$
and $a_{2} = 2 (2) + 3 = 7$
common difference $d = 7 - 5 = 2$
sum of first n terms $S_{n} = \frac{n}{2} [2 a + (n - 1) d]$
$S_{n} = \frac{n}{2} [2 \times 5 + (n - 1) 2]$
$S_{n} = n [5 + n - 1]$
$S_{n} = n (n + 4)$
$∴$ Option B is correct.

Suggest Corrections

Similar questions

Q. If the nth term of an A.P. is 2n + 1, then the sum of first n terms of the A.P. is

(a) n(n − 2)

(b) n(n + 2)

(c) n(n + 1)

(d) n(n − 1)

If the general term of a sequence is given by $\frac{(n^{2} + n)}{n}$ , then the sum of first n terms of the sequence is given by

If $S_{1}, S_{2}, S_{3} - - - - - - - - S_{n}$ denotes the sum of 1, 2, 3 ----n terms of an A.P, having first term a. If $\frac{S k x}{S x}$ k $\neq$ 1, is independent of x, then $S_{1} + S_{2} + S_{3} - - - - - - - - S_{n}$ =

If the $n^{t h}$ term of the sequence is given by $\frac{(n^{2} - 1)}{(n + 1)}$ , then the sum of first n terms of the sequence is given by

Q. The sum to

n

terms of the series

(1 \times 2 \times 3) + (2 \times 3 \times 4) + (3 \times 4 \times 5) + \dots

Join BYJU'S Learning Program

If the nth term of an A.P is 2n+3, then sum of first n term of the A.P is

The correct option is B n(n+4)Here, an=2n+3⇒a1=2(1)+3=5 and a2=2(2)+3=7common difference d=7−5=2sum of first n terms Sn=n2[2a+(n−1)d]Sn=n2[2×5+(n−1)2]Sn=n[5+n−1]Sn=n(n+4)∴ Option B is correct.

If the $n$ th term of an A.P is $2 n + 3$ , then sum of first $n$ term of the A.P is