Question

what is the sum of the first four ood natural numbers​

Answer 1

Answer:

Let the sum of first n odd numbers is Sn

Sn = 1+3+5+7+9+…………………..+(2n-1) ……. (1)

By Arithmetic Progression, we know, for any series, the sum of numbers is given by;

Sn=1/2×n[2a+(n-1)d] ……..(2)

Where,

n = number of digits in the series

a = First term of an A.P

d= Common difference in an A.P

Therefore, if we put the values in equation 2 with respect to equation 1, such as;

a=1 , d = 2

Let, last term, l = (2n-1)

Sn = ( n/2) × (a+l )

Sn = (n/2) × (1 + 2n – 1)

Sn = (n/2) × (2n) = n2

Sum of n odd numbers = n2

Step-by-step explanation:

Answer 2

Answer:

16

Step-by-step explanation:

The first four odd natural numbers are -- 1,3,5,7

1 + 3 + 5 + 7 = 16