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In How Many Ways Can a Student Choose 5 Courses Out of 9 Courses If 2 Courses Are Compulsory for Every Student? - Mathematics

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प्रश्न

In how many ways can a student choose 5 courses out of 9 courses if 2 courses are compulsory for every student?

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उत्तर

We are given that 2 courses are compulsory out of the 9 available courses,
Thus, a student can choose 3 courses out of the remaining 7 courses.
Number of ways =\[{}^7 C_3 = \frac{7!}{3! 4!} = \frac{7 \times 6 \times 5 \times 4!}{3 \times 2 \times 1 \times 4!} = 35\]

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अध्याय 17: Combinations - Exercise 17.2 [पृष्ठ १५]

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आरडी शर्मा Mathematics [English] Class 11
अध्याय 17 Combinations
Exercise 17.2 | Q 3 | पृष्ठ १५

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