What is the sum of the first 9 natural numbers?
santhu:
45
55
Answers
Answered by
2
Hi !
An AP is formed ,
1,2,3 .....
a = 1 , d = 1 , n = 9
Sn = n/2 [ 2a + [n-1]d ]
= 9/2 [ 2 + 8 ]
= 45
Sum of the first 9 natural numbers = 45
An AP is formed ,
1,2,3 .....
a = 1 , d = 1 , n = 9
Sn = n/2 [ 2a + [n-1]d ]
= 9/2 [ 2 + 8 ]
= 45
Sum of the first 9 natural numbers = 45
Answered by
2
Sum of n natural no = n (n+1)/2 = 9 x 10/2 = 45.
thank u.
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