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$ ^{20}P_3 - ^{19}P_3 = $

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The identity $^nP_r - ^{n-1}P_r = r \cdot ^{n-1}P_{r-1}$ is a useful shortcut for simplifying differences of permutations. It arises from considering whether the nth object is included in the permutation or not.

Updated On: Mar 30, 2026

$ ^{19}P_4 $
$ 4(^{19}P_4) $
$ 5!(646) $
$ 6!(646) $

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The Correct Option is D

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\( ^{20}P_3 - ^{19}P_3 = \)

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The Correct Option is D

Solution and Explanation

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