Calculate the sum of first 89 natural numbers. Select the correct option.
A) 2017 B) 2647 C) 2147 D) 2045 E) 4005
Solution   We know that(1+2+3+.....+89)	= n(n+1)/2   Therefore (1+2+3+....+89)	=(89×90 / 2)   = 4005.   Answer 4005
<result>E</result>
Calculate the sum of first 89 natural numbers.