How is computer used in banking and shopping ? ​

Assume that there is a 4% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

You wanted to look up information about alzheimer's, but you were unsure if it was spelled "alsheimer's" or "alzheimer's." which advanced search strategy would be useful? a) a boolean search b) using a wild card in your search c) trying different search engines d) doing a search for "alsheimer's not alzheimer's" asap. ill give brainlist.

8. create an abstract student class for parker university. the class contains fields for student id number, last name, and annual tuition. include a constructor that requires parameters for the id number and name. include get and set methods for each field; the settuition() method is abstract. create three student subclasses named undergraduatestudent, graduatestudent, and studentatlarge, each with a unique settuition() method. tuition for an undergraduatestudent is $4,000 per semester, tuition for a graduatestudent is $6,000 per semester, and tuition for a studentatlarge is $2,000 per semester. write an application that creates an array of at least six objects to demonstrate how the methods work for objects for each student type. save the files as student.java, undergraduatestudent.java, graduatestudent.java, studentatlarge.java, and studentdemo.java.