Count rules when conditions have different numbers of options

Scenario. A parcel desk records three pieces of information for each parcel:

• Destination: Local, National, or International
• Delivery speed: Standard or Express
• Fragile: Yes or No

Every destination can use either delivery speed, and every parcel can be fragile or not fragile.

A raw combination contains one option for every condition. For example, Local, Express, and Yes form one raw combination. A full decision table begins with one decision rule for each raw combination. How many rules are needed before cases with the same result are combined?

• 7 rules
• 8 rules
• 12 rules
• 24 rules