Question

what is the sum of the first 20 natural number ? ​

Answer 1

Sum of first n natural number is given by the formula

→ n(n+1) / 2

Here n = 20

So, Sum = 20(21) / 2

⇒ Sum = 210

Answer 2

Answer :

• 210 is the sum of first 20 natural numbers.

Given :

• 20 natural numbers

To find :

• Sum of first 20 natural numbers

Solution :

Given,

Sum of the first 20 natural numbers

• n = 20

We know that

• Sum of first natural = n(n + 1)/2

Where,

• n is natural numbers 20

↦ Sum of natural numbers = n(n + 1)/2

↦ 20(20 + 1) / 2

↦ 20(21)/2

↦ 420/2

↦ 210

Hence,

210 is the sum of first 20 natural numbers.