Algebra evaluation help?

Science & Mathematics by Anonymous 2018-06-12 02:02:10

Social Science

5 answers

Evaluate P(7,2)?

Anonymous

P(n, r) = [k = n-r+1 to n]∏k P(7, 2) = [k = 6 to 7]∏k = 6×7 = 42
Anonymous

P(7,2) Start with 7, then multiply by the next smaller integer until you have written 2 numbers. = 7 * 6 = 42
Anonymous

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Anonymous

. This is a Permutation; P(n, r) = n!/(n - r)! Unlike a Combination which is given by C(n, r) = P(n, r) / r! P(7,2) = 7!/(7 - 2)! = 7!/5! = 7*6*5! / 5! = 7 * 6 = 42
Anonymous

nPr = n! / (n - r)! 7! / (7 - 2)! => 7! / 5! => 7 * 6 * 5! / 5! => 7 * 6 => 42