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JEE Mains · Maths · STD 11 - 6. permutation and combination
The number of four letter words that can be formed using the letters of the word \(BARRACK\) is
- A \(144\)
- B \(120\)
- C \(264\)
- D \(270\)
Answer & Solution
Correct Answer
(D) \(270\)
Step-by-step Solution
Detailed explanation
If all four letters are different then the number of words \(^5{C_4} \times 4! = 120\) If two letters are \(R\) and other two different letters are chosen from \(B,A,C,K\) then the number of words \({ = ^4}{C_2} \times \frac{{4!}}{{2!}} = 72\) If two letter are \(A\) and other…
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