\(A=\{1,2,3,4,5,6,7,8\}\) के कितने (4)-तत्व उपसमुच्चय (2) और (3) दोनों को शामिल नहीं करते?
How many (4)-element subsets of \(A=\{1,2,3,4,5,6,7,8\}\) do not contain both (2) and (3) together?
Explanation opens after your attempt
Correct Answer
B. (55)
Concept
Total subsets are \(\binom{8}{4}=70\) and those containing both (2), (3) are \(\binom{6}{2}=15\). Hence (70-15=55).
Why this answer is correct
The correct answer is B. (55). Total subsets are \(\binom{8}{4}=70\) and those containing both (2), (3) are \(\binom{6}{2}=15\). Hence (70-15=55).
Exam Tip
कुल \(\binom{8}{4}=70\) हैं और (2), (3) दोनों हों तो \(\binom{6}{2}=15\) हैं। इसलिए (70-15=55) है।
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