1- To make 18 bags of snack mix, Sherry needs 4.5 cups of almonds.
As the original recipe is for 6 bags, and here Sherry wants to triple that amount. You have to multiply 1.5 x 3.
2- Sherry needs 6 cups of granola to make 12 bags of the snack mix.
If Sherry gets 6 bags using 3 cups of granola, she will get 12 by using 6 cups of granola.
3- If Sherry uses one cup of cranberries, she will need to use 2 cups of raisins.
As 1 cup of cranberries is the double of what the recipe states, Sherry should also double the amount of cups of raisins.
4- The recipe will make 2 bags of the snack mix if Sherry uses only one cup of granola.
As 1 cup of granola is a third of the amount detailed in the recipe for 6 bags, the amount of bags will also be reduced to a third. 6/3=2