6 A town council plans to plant 12 trees along the centre of a main road. The council buys the trees from a garden centre which has 4 different hibiscus trees, 9 different jacaranda trees and 2 different oleander trees for sale.
- How many different selections of 12 trees can be made if there must be at least 2 of each type of tree?
The council buys 4 hibiscus trees, 6 jacaranda trees and 2 oleander trees.
- How many different arrangements of these 12 trees can be made if the hibiscus trees have to be next to each other, the jacaranda trees have to be next to each other and the oleander trees have to be next to each other?
- How many different arrangements of these 12 trees can be made if no hibiscus tree is next to another hibiscus tree?