In how many different ways can the letters of the word AUCTION be arranged in such a way that the vowels always come together?
Aptitude
Permutation and Combination
Difficulty: Easy
Choose an option
-
A30
-
B48
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C144
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D576
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ENone of these
Answer
Correct Answer: 576
Explanation
### Concept & Permutations with Grouping
To ensure specific items are always adjacent, group them into a single super-entity. The total arrangements equal the permutations of all entities multiplied by the internal permutations of the super-entity.
### Step-by-Step Solution
* **Analyze the Word:** The word "AUCTION" contains 7 letters.
* **Identify Vowels and Consonants:**
* Vowels: A, U, I, O (4 letters)
* Consonants: C, T, N (3 letters)
* **Group the Vowels:** Treat the 4 vowels (A, U, I, O) as a single unit.
* **Count the Units:** We have the consonants C, T, N and the vowel unit (AUIO), making $3 + 1 = 4$ units in total.
* **Arrange the Units:** The 4 units can be arranged in $4!$ ways.
* $4! = 24$
* **Arrange Items Within the Unit:** The 4 vowels can be arranged internally in $4!$ ways.
* $4! = 24$
* **Calculate Total Arrangements:** Multiply the independent arrangements.
* Total ways = $24 \times 24 = 576$
### Exam Strategy & Shortcut
Recognize that neither the vowels nor the consonants have repeating letters. Apply the direct logical formula: $(C+1)! \times V!$, where $C = 3$ and $V = 4$. So, $4! \times 4! = 576$.
### Common Pitfall
Mistaking the vowel count. Missing one vowel while scanning the word (like missing the 'I' or 'O') changes the calculation entirely. Always cross-check your letter tally with the original word length.
### Final Answer
Therefore, the correct answer is **576**.