Question

Find out the sum of first 20 natural numbers:

• A. 210
• B. 230
• C. 200
• D. 420

Answer 1

The correct option is A 210

Here,
First 20 natural numbers are as follows:
1 + 2 + 3 + 4 +.......+ 20

Sum $=\frac{n(n+1)}{2}$
$=\frac{20\left(21\right)}{2}$
$=210$