Permutations of BANANA: How many distinct permutations of the letters in BANANA are possible?

Aptitude Permutation and Combination Difficulty: Easy
Choose an option
  • A
    270
  • B
    60
  • C
    120
  • D
    360

Answer

Correct Answer: 60

Explanation

Introduction / Context:BANANA contains repeated letters, so we count distinct permutations by dividing total factorial by repeated-letter factorials.

Given Data / Assumptions:Letters: A×3, N×2, B×1; total letters = 6.

Concept / Approach:Distinct permutations = 6! / (3! * 2!).

Step-by-Step Solution:

6! = 720Divide by 3! = 6 ⇒ 120Divide by 2! = 2 ⇒ 60

Verification / Alternative check:Sanity check with smaller multisets (e.g., AAB) supports the approach.

Why Other Options Are Wrong:270, 120, 360 are not equal to 6!/(3!*2!).

Common Pitfalls:Missing one of the repeated-letter divisors.

Final Answer:60

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