How can a developer check the test coverage of active Process Builder and Flows deploying them in a Changing Set?

A developer must create a ShippingCalculator class that cannot be instantiated and must include a working default implementation of a calculate method, that sub-classes can override.
What is the correct implementation of the ShippingCalculator class?

While writing a test class that covers an OpportunityLineItem trigger, a Developer is unable to create a standard PriceBook since one already exists in the org.
How should the Developer overcome this problem?

A developer is asked to create a custom visualforce page that will be used as a dashboard component. Which three are valid controller options for this page? Choose 3 answers

When would a developer use a custom controller instead of a controller extension? Choose 2 answers: