Formula Field with Pick list Fields

Formula Field with Pick list Fields

Hi,

I am trying to create a formula field for the following:

I have a few Pick list fields and each of those fields will be either "Yes"or "No". So when a field is "Yes" I want to be able to add 0.5 in the formula field so if I have 5 Pick list fields marked with "Yes" it should calculate to 2.5.

Thanks for your help.