English

Three balls are drawn from a bag containing 5 red, 4 white and 3 black balls. The number of ways in which this can be done if at least 2 are red is ______.

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Question

Three balls are drawn from a bag containing 5 red, 4 white and 3 black balls. The number of ways in which this can be done if at least 2 are red is ______.

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Solution

Three balls are drawn from a bag containing 5 red, 4 white and 3 black balls. The number of ways in which this can be done if at least 2 are red is 80.

Explanation:

We have 5 red, 4 white and 3 black balls out of which atleast 2 red balls are to be drawn

∴ Number of ways = 5C2 × 7C1 + 5C3

= 10 × 7 + 10

= 70 + 10

= 80

Hence, the value of the filler = 80.

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Chapter 7: Permutations and Combinations - Exercise [Page 126]

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NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 7 Permutations and Combinations
Exercise | Q 45 | Page 126

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