Calculate the sum of the first 20 natural numbers.
Note
The sum of first n natural numbers is n(n+1)/2; for n=20 the sum is 20×21/2 = 210.
Calculate the sum of the first 20 natural numbers.
The sum of first n natural numbers is n(n+1)/2; for n=20 the sum is 20×21/2 = 210.