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From a Class of 12 Boys and 10 Girls, 10 Students Are to Be Chosen for a Competition; at Least Including 4 Boys and 4 Girls. the 2 Girls Who Won the Prizes Last Year Should Be Included. in How Many - Mathematics

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प्रश्न

From a class of 12 boys and 10 girls, 10 students are to be chosen for a competition; at least including 4 boys and 4 girls. The 2 girls who won the prizes last year should be included. In how many ways can the selection be made?

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उत्तर

Two girls who won the prizes last year are to be included in every selection.
So, we have to select 8 students out of 12 boys and 8 girls, choosing at least 4 boys and 2 girls.
Number of ways in which it can be done =\[{}^{12} C_6 \times^8 C_2 + {}^{12} C_5 \times^8 C_3 + {}^{12} C_4 \times^8 C_4 = 25872 + 44352 + 34650 = 104874\]

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अध्याय 17: Combinations - Exercise 17.2 [पृष्ठ १६]

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आरडी शर्मा Mathematics [English] Class 11
अध्याय 17 Combinations
Exercise 17.2 | Q 7 | पृष्ठ १६

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