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If n Pr=^n P(r+1) and n Cr=^n C(r-1,) ...

If `n P_r=^n P_(r+1)` and `n C_r=^n C_(r-1,)` then the value of `(n+r)` is.

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If ^n P_r=^n P_(r+1)a n d^n C_r=^n C_(r-1,) then the value of n+r is.

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CENGAGE ENGLISH-PERMUTATIONS AND COMBINATIONS-All Questions
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