Answer:
Step-by-step explanation:
Given
there are 12 blue balloon
9 green lanterns
6 red ribbons
Total no of ways in which decoration can be done=(12+9+6)!=27 !
Considering red ribbons as single unit, so there are 22 units
so no of ways in which they are arranged [tex]=22!\times 6![/tex]
6! is multiplied because 6 ribbons can be arranged in 6! ways
No of ways in which decoration is done, such that no two ribbons are next to each other [tex]=27 !- 22 !\times 6![/tex]