Permutations and Combinations?

Problem: 6 parking spots to share with 10 possible contract types in 21.67 weekdays / month

Memberships | Fee | Access Monday to Friday | Extra Features

A: Plan Lite $175.00 / month 9:30am to 5:30pm 3days a week. B: "Keys to garage with unlimited nights and weekend, only 75$ extra per month."

C: Plan U-lite $60.00 / month 9:30am to 5:30pm 3days a month D,E,F: "Additional days only 15$/each Minimum of 3 days."

G: Plan Shopper $25.00 / month 9:30am to 5:30pm 1days a month H,I,J: "Additional days only 15$/each Minimum of 3 days."


The Limits:

1 membership with 2 options, 2 membership types with 4 options each = 10 possible types of contracts (A,B,C,D,E,F,G,H,I and J).
The lot is fully rented at all times and may have all of one type of contract, and even mix of all 10 types or, any one can be dominant with a mix of the other type.
Note: it is possible that 0 "unlimited nights and weekends" are sold - or - that a maximum of 6 "unlimited nights and weekends" are sold. There are only 6 parking spots.

Questions:

1. How many possible combinations of contracts types are there with every weekday having all spots parked on?

2. What is the Maximum and Minimum customers that can have contracts and still get parking?

3. What is the Maximum and Minimum income return from the parking with the lot fully rented at all times?

4. What is the most effective combination of contracts to get the most occupancy and highest return?