Question 5
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Five letters are put at random into five addressed envelopes. In how many ways can every letter go into a wrong envelope?
- A 120
- B 60
- C 53
- D 44 Correct
Correct Answer: Option D
Derangements of 5: 5! (1 − 1 + 1/2 − 1/6 + 1/24 − 1/120)
= 60 − 20 + 5 − 1 = 44
Answer: 44
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