In: Statistics and Probability
If all permutations of the letters of the word "BEFORE" are arranged in the order as in a dictionary. What is the 32 word?
Distinct letters of the given word in dictionary order ={B, E, F, O, R}
Total number of letters =6 (say, 6 boxes).
No. of distinct letters =5 (B, E, F, O, R).
No. of repeated letters =2 (E, E).
So, the 6 boxes has to be filled with 6 letters in which two letters are the same (E, E).
No. of letters stating with B =5! =120
So, it's difficult to find 32nd word unless we write all 32 words in dictionary order with or without meaning.
No. of letters starting with BE =4! =24
(since after filling BE, we are left 4 boxes that are filled using the letters F, O, R, E).
No. of words starting with BF =4!/2! =24/2 =12
(since after filling BF, we are left with 4 boxes that are filled using the letters O, R, E, E. The letter E is repeated twice and so, we divide 4! by 2!).
Till now we have 24+12 =36 words but we need 32nd word. So, let's write last five words of these 36 words which have to be written in reverse dictionary order in order to get 32nd word.
36. BFROEE
35. BFREOE
34. BFOREE
33. BFOERE
32. BFEROE
So, 32nd word is BFEROE
Or we can write it as: Bferoe