NTA Abhyas JEE Main2020MathematicsPermutation and CombinationPractice
The number of ways of arranging the letters AAAAA, BBB, CCC, D, EE and F in a row, if the letters B are separated from one another, is equal to
Options
- A13 ! 5 ! 3 ! 3 ! 2 !
- B14 ! 3 ! 3 ! 2 !
- C15 ! 3 ! 2 2 ! 5 !
- DC 3 13 × 12 ! 5 ! 3 ! 2 !
Correct answer
D. C 3 13 × 12 ! 5 ! 3 ! 2 !
Step-by-step solution
All AAAAA , CCC , D , EE , F can be arranged in 12 ! 5 ! 3 ! 2 ! ways. Between the gaps B can be arranged in C 3 13 ways Hence, the total number of ways = C 13 3 × 12 ! 5 ! 3 ! 2 !