Permutations And Combinations Question 301

Question: The number of arrangements of the letters of the word BANANA in which two N?s do not appear adjacently is [IIT Screening 2002]

Options:

A) 40

B) 60

C) 80

D) 100

Show Answer

Answer:

Correct Answer: A

Solution:

  • Required number of arrangements = (Total number of arrangements) - (Number of arrangements in which N?s are together) $ =\frac{6!}{2!\times 3!}-\frac{5!}{3!}=60-20=40 $ .