Problem
A mobile phone service provider has three different subscription packages for its customers:
Package A: For $39.99 per month 450 minutes are provided. Additional minutes are $0.45 per minute
Package B: For $59.99 per month 900 minutes are provided. Additional minutes are $0.40 per minute.
Package C: For $69.99 per month unlimited minutes provided.
Your program should ask which package the customer has purchased and how many minutes were used.
Then, it displays the customer's monthly bill and how much money the customer would save if she purchased the other two packages. If there would be no savings, "No Saving" should be printed.
Use constants for menu choices. Use constants for base package rates. Use constants for the minutes provided. Use constants for additional minute rates. Use the switch statement.