Engineering
Mathematics
Permutation and Combination Basic Definitions
Question
Consider a class of 5 girls and 7 boys. The number of different teams consisting of 2 girls and 3 boys that can be formed from this class, if there are two specific boys A and B, who refuse to be the members of the same team, is
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Solution
Number of ways = Total number of ways without restriction – When two specific boys are in team without any restriction, total number of ways of forming team is 7C3 × 5C2 = 350 If two specific boys B1, B2 are in same team then total number of ways of forming team equals to 5C1 × 5C2 = 50 ways total ways
= 350 – 50 = 300 ways