Question
Question: No of words formed by the letters of the word HINDUSTA which begin and end in a vowel are?...
No of words formed by the letters of the word HINDUSTA which begin and end in a vowel are?
4320
Solution
To form words from the letters of HINDUSTA that begin and end in a vowel:
-
Identify Letters and Categories:
The word HINDUSTA has 8 distinct letters: H, I, N, D, U, S, T, A.
Vowels: I, U, A (3 vowels)
Consonants: H, N, D, S, T (5 consonants) -
Place the First Vowel:
The first position of the word must be a vowel. There are 3 choices for this position (I, U, or A).
Number of ways to fill the first position = 3. -
Place the Last Vowel:
The last position of the word must also be a vowel. Since one vowel has already been placed in the first position, there are 2 vowels remaining.
Number of ways to fill the last position = 2. -
Arrange the Remaining Letters:
After placing two vowels at the beginning and end, there are 8 - 2 = 6 letters remaining. These 6 letters are the 5 consonants and the 1 vowel that was not used. All these 6 letters are distinct.
There are 6 remaining positions in the middle of the word. These 6 distinct letters can be arranged in these 6 positions in 6! ways.
6! = 6 × 5 × 4 × 3 × 2 × 1 = 720. -
Calculate the Total Number of Words:
To find the total number of words satisfying the conditions, multiply the number of ways for each step:
Total words = (Ways to choose first vowel) × (Ways to choose last vowel) × (Ways to arrange remaining letters)
Total words = 3 × 2 × 6!
Total words = 6 × 720
Total words = 4320