WBJEE · Maths · Permutation Combination
There are 7 greeting cards, each of a different colour and 7 envelopes of same 7 colours as that of the cards. The number of ways in which the cards can be put in envelopes, so that exactly 4 of the cards go into envelopes of respective colour is,
- A \({ }^{7} C_{3}\)
- B \(2^{7} C_{3}\)
- C \(3!^{4} C_{4}\)
- D \(3!^{7} C_{3}^{4} C_{3}\)
Answer & Solution
Correct Answer
(B) \(2^{7} C_{3}\)
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