There are three main setting combinations categories for washing machine as
{Regular, delicate, or extra dirty}
{hot, warm, or cold water}
{regular rinse, or extra rinse}
Now we have to find about how many different setting combinations are there in washing machine.
First category {Regular, delicate, or extra dirty} has 3 choices So machine can be set into any one of these 3 options.
Second category {hot, warm, or cold water} has 3 choices So machine can be set into any one of these 3 options.
Third category {regular rinse, or extra rinse} has 2 choices So machine can be set into any one of these 2 options.
Combining all three catagories, we will able to get 3*3*2 or 18 different setting combinations for the washing machine.
Hence 18 is the final answer.