How to calculate a value based on multiple dropdown lists

I have 3 dropdown lists created, where each option in each list has a corresponding value. The value is written in the column directly to the right of the list option. All the values are 1 or lower, ie. 0.9, 0.8 and so on.

I'm looking for a formula to put in an empty cell that will automatically calculate a value based on the options chosen in the 3 dropdown lists. In this particular case, the value should never be higher than 12. This is why the values that correspond to the dropdown list options have a maximum of 1.

Basically, I want the number 12 to be multiplied by all 3 values that correspond with the options chosen 3 dropdown lists.

Is there any formula could do this? Do I have to change something first?