Question

3. If all words with 2 distinct vowels and 3 distinct consonants were listed alphabetically, what
would be the rank of "ACDEF? *
(1 Point)
4716
4720
4718
4717​

Answer 1

The words that comes ahead of “ACDEF’ start with AB, ACB, ACDB and ACDEB

The number of words that start with AB = 4C1 * 20C2 *3! = 4560

(We have to select 1 vowel out of remaining 4 and 2 consonants out of remaining 20. The number of ways to arrange last 3 alphabets is 3!, as the first 2 are fixed)

The number of words that start with ACB = 4C1 * 19C1 *2! = 152

(We have to select 1 vowel out of remaining 4 and 1 consonant out of remaining 19. The number of ways to arrange last 2 alphabets is 2!, as the first 3 are fixed)

The number of words that start with ACDB = 4C1*1! = 4

(We have to select 1 vowel out of remaining 4 )

Total word that comes ahead of “ACDEF" = 4560+152+4+1= 4717

Rank= 4717+1= 4718

Answer 2

Answer:

Why is the previous answer using Combinations and not Permutations. Please somebody clarify

Step-by-step explanation: