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A group consists of 4 girls and 7 boys. In how many ways can a team of 5 members be selected if the team has (1) no girl (ii) at least one boy and one girl. |
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Answer» Given 4 girls and 7 boy's (i) no girls: Total number of selection = 4C0 x 7C5 = 1 x (7!/(5! x 2!) = [(7 x 6)/2] = 21 ways (ii) atleast 1 boy and 1 girls Girls × boys (a) 4C1 × 7C4 = 7 (b) 4C2 × 7C3 = 84. (c) 4C3 × 7C2 = 210 (d) 4C4 × 7C1 = 140 Total number of selection 441 ways . |
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