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Find rif(i)5P,-26P,-1(ii)"P,=6P,-1 |
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Answer» Explanation : nPr = n!/(n-r)! i) 5Pr = 2*6P(r-1) 5!/(5-r)! = 2*6!/(6-r+1)! 5!/(5-r)! = 2*6×5!/(7-r)! 1/(5-r)! = 12/((7-r)(6-r)(5-r)!) (7-r)(6-r) = 4×3 r = 3 ii) 5Pr = 6P(r-1) 5!/(5-r)! = 6!/(6-r+1)! 5!/(5-r)! = 6×5!/(7-r)! 1/(5-r)! = 6/((7-r)(6-r)(5-r)!) (7-r)(6-r) = 3×2 r = 4 Answer : i) r = 3 ii) r = 4 If you find this answer helpful then like it thnq |
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