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In how many different ways can the letters of the word 'DETAIL' be arranged so that the vowels occupy only the odd positions?

Difficulty: Medium

Correct Answer: 36

Explanation:

Problem restatement
Place the vowels of 'DETAIL' in odd positions (1, 3, 5) and the consonants in the remaining even positions (2, 4, 6).


Given data

  • Word: D, E, T, A, I, L (6 distinct letters).
  • Vowels: E, A, I (3 vowels).
  • Odd positions available: 1, 3, 5 (exactly 3 slots).

Concept/Approach
Assign the 3 vowels to the 3 odd slots and the 3 consonants (D, T, L) to the 3 even slots independently.


Step-by-step calculation
Arrange vowels in odd slots: 3! = 6 Arrange consonants in even slots: 3! = 6 Total arrangements = 6 × 6 = 36


Verification/Alternative
Because the counts match exactly (3 odd slots and 3 vowels), no combinations factor is needed; only permutations within positions.


Common pitfalls

  • Allowing vowels in even positions or forgetting to permute consonants separately.

Final Answer
36

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