Question

Find the sum of the first 18 odd positive integers.

Answer 1

Answer:

The sum of the first 18 odd positive integers is 324.

Step-by-step explanation:

Given : The first 18 odd positive integers.

To find : The sum of the first 18 odd positive integers?

Solution :

The odd positive integers are 1,3,5,.... forming an Arithmetic sequence .

Where, First term is a=1

Common difference is d=2

Number of terms n=18

The sum of A.P formula is

$S_n=\frac{n}{2}[2a+(n-1)d]$

Substitute the values in the formula,

$S_{18}=\frac{18}{2}[2(1)+(18-1)2]$

$S_{18}=9[2+(17)2]$

$S_{18}=9[2+34]$

$S_{18}=9[36]$

$S_{18}=324$

Therefore, The sum of the first 18 odd positive integers is 324.