1. Please write the class diagram that models the following Telephony System.

The company Smart Telecom wants to sell mobile numbers to their users. Each user has one

telephone number. When users register in the system, users need to provide their identification

document (e.g., passport or national ID) and their address. Then, each user selects his/her rate

plan that controls how they will be charged for their calls. Besides, users have an unlimited

number of offers (e.g., international calls offer) to reduce the calls' fees. Offers have an expiration

date. Offers also can contradict each other. The system records the conflicting offers, so users

cannot enroll in such offers. For example, user A cannot get both offers C and D as such offers

are contradicting. The company has outdated (not used) offers and rate plans. The company

assigned an analytics team to assess the most used rate plans/offers and the outdated ones.

When registering a new user, the user defines her/his billable entity (i.e., the person who will pay

for the calls). For example, each student can buy a new telephone number and assign their

parents as a billable entity. The system tracks the assigned users and limits up to 8 users per

billable entity. When creating a new user, the system makes a dummy call to allow the user data

to be stored in the system.

The system tracks the ongoing calls for the users. At the end of each month, the system charges

the billable entity (e.g., parents) to use the associated users using the billing account of the

billable entity.

2. Given the following model, please answer the following questions.

1) What is the minimum number of calories burned per day for each person?

2) Please draw the object diagram of the model.

3) Please modify the model to include the following characteristics.

A person has the total burned calories per day.

Each day, a person needs to do at least three activities.

A person can perform an activity on a certain day. The performed activity

impacts the total burned calories on this day.

Activity * * - burnedCalories : double Person Day BurnedCalories is greater than 10 Calories