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Question
The sum of first n natural numbers is given by `1/2n^2 + 1/2n`. Find the sum of first 5 natural numbers.
Solution
Given, sum of first n natural numbers = `1/2n^2 + 1/2n`
Sum of first 5 natural numbers = `1/2(5)^2 + 1/2(5)` ......[Put n = 5]
= `25/2 + 5/2`
= `30/2`
= 15
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