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The sum of first n numbers of the form (...

The sum of first n numbers of the form `(5k + 1)`, where `k in I^+` is :

A

`n/2[5n^2-3]`

B

`n(20-3n)`

C

`n/2[5n+7]`

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
C
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