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Evaluate n!(n-r)!, when n = 9, r = 5

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प्रश्न

Evaluate `(n!)/((n-r)!)`, when n = 9, r = 5

योग
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उत्तर

When n = 9, r = 5  `(n!)/((n-r)!)  = (9!)/((9 - 5)!) = (9!)/(4!) = (9  xx 8  xx 7  xx 6  xx  5  xx  4!)/(4!)`

= 9 x 8 x 7 x 6 x 5 = 15120 

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अध्याय 6: Permutations and Combinations - EXERCISE 6.2 [पृष्ठ १०७]

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एनसीईआरटी Mathematics [English] Class 11
अध्याय 6 Permutations and Combinations
EXERCISE 6.2 | Q 5. (ii) | पृष्ठ १०७

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