Without adding, find the sum of the following:

$1+3+5+7+9+11+13$

Academic Mathematics NCERT Class 8

Given :

The given expression is $1+3+5+7+9+11+13$

To do :

We have to find the sum without adding.

Solution :

We know that,

The Sum of 'n' consecutive odd numbers is $n^2$.

In the given sum there are 7 consecutive odd numbers.

Therefore,

$n = 7$

$n^2 = 7^2 =49$.

$1+3+5+7+9+11+13 = 49$.

Therefore, the sum of the given expression is 49.

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Updated on: 10-Oct-2022

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