Progression (Sequence and Series)Hard
Question
The series of natural numbers is divided into groups as follows ; (1), (2,3), (4,5,6), (7,8,9,10) and so on. Find the sum of the numbers in the nth group is-
Options
A.
[n(n2 + 1)]
[n(n2 + 1)]B.
C.
D.
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