Q2 of 27 Page 97

How many consecutive natural numbers starting from 1 should be added to get 300?

Formula used/Theory


Sum of ‘n’ natural numbers = n(n + 1)/2


Sum = 300


∴ 300 = n(n + 1)/2


300×2 = n(n + 1)


600 = n(n + 1)


n2 + n–600 = 0


As comparing eq to ax2 + bx + c = 0


x = = 24


x = = –25


Counting of numbers cannot be negative


∴ x = 24


Conclusion/Result. Sum of 24 natural numbers is 300


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