Question

If there are balls numbered {1,2,3,3,3} . What are the number of possible arrangements if only 4 balls are selected .the ordering matters!

Answer 1

use permutation with repetition, 3 is being repeated 3 times

Answer 2

The thing I am confused is about , like if I said permutation of all the five numbers it would be 5!/3! .. But since now i have to choose only 4. Can you provide a mathematical step. thanks

Answer 3

Just a quick hint , permutation is selecting an arranging thing in certain order. Order matters unlike combination.