Write a complete C program including declaration of function(s), the function(s) code, and main with its call to the function(s).

Do these standard problems in full code:

finding the average of a bunch of numbers till the user enters 0.

finding the prime numbers from 0 to n where n is the input.

finding factorials. Do this using loops, and recursive functions.

find the average of all prime numbers between 0 to n.

finding the total of all doubles (or cubes...) between a range 0 to n.