The probability that in a random arrangement of the letters of the word 'ANIMAL', the two A's come together.
1/3
The total number of words which can be formed by permuting the letters of the word 'ANIMAL' is 6!2! as there are two A's.
Hence n(S)=6!2!
Taking two A's as one letter, the number of ways of arrangement in which both A's are together = 5!
So n(X)=5!
Hence required probability=n(X)n(S)=13