Class 11

Math

Algebra

Permutations and Combinations

In how many ways can $2$ identical green chairs and $4$ identical yellow chairs be arranged in a row?

- $6$
- $15$
- $21$
- $24$
- $30$

- We can arrange $4$ identical yellow chairs and $2$ identical green chairs in $4!2!(4+2)! =4!2!6! =15$