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Find n and r if, nPr = 720 and nCn-r = 120 n

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Find n and r if, nPr = 720 and nCn-r = 120 n

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nPr = 720

\(\therefore\) n(n - 1)(n - 2) = 10 x 9 x 8

\(\therefore\) n = 10

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