Question

the sum of all odd number less than 10

Answer 1

Odd number from 0 to 10
= 1 + 3 + 5 + 7 + 9
=25

Answer 2

$Hey \: \: there \:$
Let S be the sum of the Number and n be the Number of terms

Given that -

Sum of all odd number -

➯ First we need to know

what is odd number ?

➣ odd number is a number which has a remainder of 1  upon division by 2

We know that from 1 - 10 there are following number are odd -

1 , 3 , 5 , 7 , and even 9

here , a = 1

d = 3-1 = 2

aₙ = 9

So , S₅ = 5/ 2 × ( 1 + 9 )

=> 5/2 × 10

=> 5× 5

=> 25


Hence the sum of Odd number less than 10 ( S₅ ) is 25

⦿ Hope this would help you ⦿