Which one of the following best defines the term operating system?
a. the software that allows computer users to run applications with the hardware of a specific system. microsoft® windows® or apple® computer's os are examples of operating systems.
b. the master control program that manages a computer's internal functions and provides a means of control to the computer's operations and file system.
c. the software that manages the hardware and software interface of a computer.
d. all of the above.

Write a loop that reads positive integers from standard input and that terminates when it reads an integer that is not positive. after the loop terminates, it prints out, on a line by itself and separated by spaces, the sum of all the even integers read, the sum of all the odd integers read, a count of the number of even integers read, and a count of the number of odd integers read, all separated by at least one space. declare any variables that are needed. assume the availability of a variable, stdin, that references a scanner object associated with standard input. that is, stdin = new scanner(system. in); is given.

Write a program that displays the following menu: geometry calculator 1. calculate the area of a circle 2. calculate the area of a rectangle 3. calculate the area of a triangle 4. quit enter your choice (1-4): if the user enters 1, the program should ask for the radius of the circle and then display its area. use the following formula: area = ď€(the square of r) use 3.14159 for ď€ and the radius of the circle for r. if the user enters 2, the program should ask for the length and width of the rectangle and then display the rectangle’s area. use the following formula: area = length * width if the user enters 3, the program should ask for the length of the triangle’s base and its height, and then display its area. use the following formula: area = base * height * .5 if the user enters 4, the program should end. input validation: display an error message if the user enters a number outside the range of 1 through 4 when selecting an item from the menu. do not accept negative values for the circle’s radius, the rectangle’s length or width, or the triangle’s base or height. note: if the user enters an improper menu choice (1-4), the program prints "the valid choices are 1 through 4. run the program again and select one of those." if the user enters a negative radius, the program prints "the radius can not be less than zero." if the user enters a negative value for height or base, the program prints "only enter positive values for base and height."

Write a fragment of code that reads in strings from standard input, until end-of-file and prints to standard output the largest value. you may assume there is at least one value. (cascading/streaming logic, basic string processing)