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Five students are selected from 11. How many ways can these students be selected if two specified students are selected? - Mathematics and Statistics

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प्रश्न

Five students are selected from 11. How many ways can these students be selected if two specified students are selected?

योग
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उत्तर

Number of students = 11
Number of students to be selected = 5
Here, 2 specified students are included.
So, we need to select 3 more students from the remaining 9 students.
This can be done in:
= `""^9"C"_3`

= `(9 xx 8 xx 7)/(3 xx 2 xx 1)`

= 84 ways
∴ Number of required selections
= 84 × 1 × 1
= 84
Thus, 84 selections. can be made such that 2 specified students are included.

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Properties of Combinations
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 6: Permutations and Combinations - Exercise 6.7 [पृष्ठ ९०]

APPEARS IN

बालभारती Mathematics and Statistics 2 (Commerce) [English] 11 Standard Maharashtra State Board
अध्याय 6 Permutations and Combinations
Exercise 6.7 | Q 15. (a) | पृष्ठ ९०

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