Question

find the sum of first 30 natural numbers of AP whose term is 3n+ 2​

Answer 1

Step-by-step explanation:

hope it might help you.

Answer 2

There are 2 ways of finding the sum of n term:

$S_n = \dfrac{n}{2} (2a + (n - 1)d) \text{ where a is the first term and d is the constant difference}$

OR

$S_n = \dfrac{n(a + l)}{2} \text { where a is the first term and l is the last term}$

Find the first term:

$a_n = 3n + 2$

$a_1 = 3(1) + 2$

$a_1 = 5$

Find the last term:

$a_n = 3n + 2$

$a_{30} = 3(30) +2$

$a_{30} = 92$

Find the sum of the first 30 terms:

$S_n = \dfrac{n(a + l)}{2}$

$S_{30} = \dfrac{30(5 + 92)}{2}$

$S_{30} = 1455$

Answer: The sum of the first 30 term is 1455.