What is the primary reason to use inheritance? when you want to include multiple classes in the same .java file when there is an "is-a" relationship when you want to avoid duplicating code when there is a "has-a" relationship

When would you be most likely to use an abstract class? when you need to derive a class from Object when every method in the class is concrete when you need a super class that should not be instantiated when you need a super class that can be instantiated alongside the derived classes =========== Which UML symbol represents aggregation? a filled triangle an unfilled diamond an unfilled triangle a filled diamond

. Draw an inheritance hierarchy representing parts of a computer system (processor, memory, disk drive, DVD drive, printer, scanner, keyboard, mouse, etc.).  (BlueJ)

Write a code using abstract data types, classes, and inheritance methods as in the example below. Do not use the car class exemplified, but think of any similar use of such a class and adapt it to your idea. Make sure to follow all the requirements set below: Creating the Car Class Motorvehicles Solutions, Inc. is a business that sells cars and leasing services. You are a programmer in the company's IT department, and your team is designing a program to manage all of the cars that are in the inventory. You have been asked to design a class that represents a car. The data that should be kept as attributes in the class are as follows: The name of the car's manufacturer will be assigned to the __manufact attribute.  The car's model number will be assigned to the __model attribute The car's retail price will be assigned to the __retail_price attribute The car's leasing price will be assigned to the __leasing_price attribute The class will also have the following methods: An __init__…