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प्रश्न
Choose the correct alternative:
If Pr stands for rPr then the sum of the series 1 + P1 + 2P2 + 3P3 + · · · + nPn is
विकल्प
Pn + 1
Pn + 1 – 1
Pn + 1 + 1
`""^(("n" + 1))"P"_(("n" - 1))`
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उत्तर
Pn + 1
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