Question

iii) What is the sum of the first 10 natural numbers?
a) 55
b) 20
c) 65
d) 11
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Answer 1

Hence, the sum of first n numbers is n(n+1)2 . Hence the sum of the first 10 terms, 1+2+3+...+10=55 .

Hence, option a) is correct answer ✌

Answer 2

[ A ] 55

The sum of the first 10 natural numbers is 5

Explaination

Let us make better easy :

N = 10

A = 1

D = 1

= Then the sum of first 10 natural number is :-

= Sn = n/2 { 2a + (n - 1)d}

= S 10= 10/2 { 2(1) + ( 10-1 ) 1 }

= 5 ( 2+9)

= 5 ( 11 )

= 55

Hence , we get the answer .