a. Write a program to calculate the average score for uncertain number of students. 1. Define variables-score, student_no and sum 2. Use sentinel controlled structure to do the following: Ask user to input an integer as student score. Please do the error checking for the score. The range of score is between 0 and 100. If the score is not in the range, please display an error message and ask user to input a new score. Add the valid score to sum a. b. c. Repeat step a and b until user input a user defined sentinel value to stop the loop 3. Define a function to calculate the average - dividing sum by student_no. Please note that the average is float not integer. 4. Display the number of students, total points, and average (2 decimal places). 1b. Write a program to calculate the average score for certain number of student. 1. Define 10 elements integer array, and sum. 2. Use counter controlled structure to do the following: a. Use random generator to generate 10 integers between 0 and 100. b. Store the integers into array c. Add the score into sum. 3. Define a function to calculate the average - dividing sum by student_no. Please note that the average is float not integer. 4. Display the students' scores, total points, and average (2 decimal places).