Find in how many different ways, the letters of the word ‘LEADING’ can be…

2023

Find in how many different ways, the letters of the word ‘LEADING’ can be arranged in such way that the vowels always come together?

  1. A.

    548

  2. B.

    689

  3. C.

    720

  4. D.

    786

Attempted by 5 students.

Show answer & explanation

Correct answer: C

Step-by-Step Solution

  1. Analyze the word: The word 'LEADING' has 7 unique letters: L, E, A, D, I, N, G.

  2. Identify vowels and consonants:

    • Vowels: E, A, I (3 vowels)

    • Consonants: L, D, N, G (4 consonants)

  3. Group the vowels: Since the vowels must always come together, we treat them as a single entity or 'block'. Let's call this block (EAI).

  4. Count the items to arrange: Now, we arrange the 4 consonants (L, D, N, G) and the 1 vowel block (EAI). This gives us a total of 5 entities (4 + 1 = 5).

    • The number of ways to arrange these 5 entities is 5! (5 factorial).

    • 5! = 5 * 4 * 3 * 2 * 1 = 120 ways.

  5. Arrange within the vowel block: The 3 vowels (E, A, I) inside their block can be arranged among themselves in 3! ways.

    • 3! = 3 * 2 * 1 = 6 ways.

  6. Calculate the total arrangements: By the fundamental counting principle, we multiply these values:

    • Total ways = 120 * 6 = 720 ways.

Explore the full course: Amcat Preparation