Vanya prepared 4 different letters to 4 different addresses. For each letter, she prepared one envelope with its correct address. If the 4 letters are to be put into the four envelopes at random, what is the probability that only one letter will be put into the envelope with its correct address?	Choose the correct option: A) 1/24 B) 1/8 C) 1/4 D) 1/3 E) 3/8
Total Vanya# of ways - 4! = 24.   1/3esired:   A-Mapped to the only correct address----------x 1 way only   B-Mapped to other two incorrect addresses - x 2 ways   C-Mapped to other two incorrect addresses - x 2 ways   1/3-Mapped to other two incorrect addresses - x 2 ways   Therefore, 1*2*2*2/24 = 1/3.?
<result>D</result>
Vanya prepared 4 different letters to 4 different addresses. For each letter, she prepared one envelope with its correct address. If the 4 letters are to be put into the four envelopes at random, what is the probability that only one letter will be put into the envelope with its correct address?