In linux operating system, what file extension is used forexecutable files?

The purpose of this problem is to write some small functions and practice passing things around amoung functions.1) the main function shall ask the user to enter three numbers and read the three numbers.2) write a function named findsum that takes three numbers as arguments and returns their sum. the main function shall call this function.3) write a function named findaverage that takes the sum and the number of numbers and returns the average. the main function shall call this function.4) write a function named findsmallest that takes the three numbers and returns the smallest value. the main function shall call this function.5) the main function shall print the results in the following format, with two decimal positions and the decimal points aligned: