Question

find the sum of the following 1+4+7....…22 terms​

Answer 1

Answer:

Given:

•  1+4+7......... upto 22

To find :

• the sum upto 22

Solving Question:

 Arithmetic progression:

  it a sequence of number obtained by adding a fixed number to the previous term.

$S_n=\dfrac{n}{2}(2a+(n-1)d)$

Solution:

n = 22

a = 1

d = 3

 substitute the values in the equation.

⇒$\dfrac{22}{2}(2*1+(22-1)*3)\\\\\implies 11(2+21*3)\\\\\implies 11(2+63)\\\\\implies 11(65)\\\\\implies 715$

Therefore, the sum of the sequence is 715