Calculate Sales Tax

Problem

The sales tax in Australia is called the goods and services tax (GST) of 10%, which is applied to most products and services. For example, in a physio clinic, medical services such as physiotherapy are GST-free. However, GST applies to pilates classes (also a service), and also to all products sold at the clinic. All businesses must show GST-inclusive prices. For example, for a $10 meal, $9.09 is the net amount and $0.91 is sales tax.

Write a program below that defines the Goods and ServiceItem classes. Ensure that objects of both types can invoke the methods, net_amount and gst, to calculate the net amount and sales tax of products and services.

Expected Output

We can test the class definitions you provide with code as shown below: