CUET PG 2021 — Mathematics PYQ
CUET PG | Mathematics | 2021How many distinguishable permutations of the letters are there in the word BANANA?
Choose the correct answer:
- A.
720
- B.
120
- C.
60
(Correct Answer) - D.
360
60
Explanation
1. Identify the total number of letters and frequencies
The word is BANANA.
-
Total number of letters (n) = 6
-
Frequency of B = 1
-
Frequency of A = 3
-
Frequency of N = 2
2. Apply the Formula
The formula for the number of distinguishable permutations is:
Permutations=n1!⋅n2!⋅⋯⋅nk!n!
Substituting our values:
Permutations=1!⋅3!⋅2!6!
3. Calculation
Calculate the factorials:
-
6!=6×5×4×3×2×1=720
-
1!=1
-
3!=3×2×1=6
-
2!=2×1=2
Now, plug these into the equation:
Permutations=1×6×2720
Permutations=12720
Permutations=60
Explanation
1. Identify the total number of letters and frequencies
The word is BANANA.
-
Total number of letters (n) = 6
-
Frequency of B = 1
-
Frequency of A = 3
-
Frequency of N = 2
2. Apply the Formula
The formula for the number of distinguishable permutations is:
Permutations=n1!⋅n2!⋅⋯⋅nk!n!
Substituting our values:
Permutations=1!⋅3!⋅2!6!
3. Calculation
Calculate the factorials:
-
6!=6×5×4×3×2×1=720
-
1!=1
-
3!=3×2×1=6
-
2!=2×1=2
Now, plug these into the equation:
Permutations=1×6×2720
Permutations=12720
Permutations=60

