2 a. Write a program to using the principle of control structures (if /else statements) determine which of the students grade, based on the marks numbers entered by the user (Using the table below)....

Extracted text: 2 a. Write a program to using the principle of control structures (if /else statements) determine which of the students grade, based on the marks numbers entered by the user (Using the table below). From То Grade 90 100 80 89 В 70 79 C 69 b. Write an algorithm to determine the average of any six (5) numbers and display the below after: The sum, the product and the average. c. Describe what is a variable and how is it used in a program.