More Questions from Permutation and Combination

In how many different ways can the letters of the word 'CORPORATION' be arranged so that the vowels always come together?

Aptitude Permutation and Combination Difficulty: Hard
Choose an option
  • A
    50400
  • B
    100800
  • C
    25200
  • D
    75600
  • E
    5760

Answer

Correct Answer: 50400

Explanation

Problem restatementArrange 'CORPORATION' with all vowels in a single block. Account carefully for repeated letters.

Given data

  • Letters (11 total): C(1), O(3), R(2), P(1), A(1), T(1), I(1), N(1).
  • Vowels: O, O, O, A, I (5 vowels, with O repeated 3 times).
  • Consonants: C, R, R, P, T, N (6 letters, with R repeated 2 times).

Concept/ApproachTreat the 5 vowels as a single block [V]. First, arrange the 7 items: [V] plus the 6 consonants (with R repeated). Then multiply by the internal arrangements of the vowels (with 3 O's repeated).

Step-by-step calculation Arrange 7 items: [V], C, R, R, P, T, N ⇒ 7! / 2! (for the two R's) = 5040 / 2 = 2520 Arrange vowels inside [V]: 5! / 3! (for three O's) = 120 / 6 = 20 Total arrangements = 2520 × 20 = 50400

Verification/AlternativeCheck counts: total letters 11; grouping vowels reduces to 7 items; duplicated R's and O's appropriately handled by dividing by factorials of repeats.

Common pitfalls

  • Forgetting to divide by 2! for the two R's in the outer arrangement.
  • Forgetting to divide by 3! for the three O's inside the vowel block.

Final Answer50400

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