Question 6

Mathematics Permutation and Combination Hard

Naresh has 10 friends, and he wants to invite 6 of them to a party. How many times will 3 particular friends never attend the party?

(A) 8
(B) 7
(C) 720
(D) 35
βœ“ Correct Answer: Option B Verified Solution

πŸ“˜ Step-by-Step Solution & Detailed Explanation:

To determine how many ways Naresh can invite 6 friends such that 3 particular friends never attend, let’s solve step-by-step:\[\] Step 1: Total number of friends excluding the 3 particular friends Naresh has \(10\) friends in total. Excluding the 3 particular friends, there are: \[ 10 - 3 = 7 \quad \text{friends remaining.} \] \[\] Step 2: Selecting 6 friends from the remaining 7 To ensure that the 3 particular friends never attend, Naresh must select all 6 friends from the remaining 7. The number of ways to choose 6 friends from 7 is: \[ \binom{7}{6} = \frac{7!}{6!(7 - 6)!} = \frac{7}{1} = 7 \] \[\] Final Answer: The number of ways the 3 particular friends never attend the party is: \[ \boxed{7} \]

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