Question
Mathematics Question on permutations and combinations
How many words can be formed from the letters of the word DOGMATIC, if all the vowels remain together :
A
4140
B
4320
C
432
D
43
Answer
4320
Explanation
Solution
Total numbers of letters in the given word = 8 Total no. of 8 letters word formed = P (8, 8) = 8! No. of vowels = 3 (i.e., O, A, I) If we consider these three vowels as one letter, then the number of different words = 8 - 3 = 5 + 1 (as 3?? vowels are considered as 1 word) Hence, the total number of 8 letters in which vowel remains together = P (3 × 3) × P (6 × 6) = 3! × 6! = 6 × 720 = 4320