Write a simple program In Java that asks the user to enter two numbers: Add numbers and display the result on the screen Example output should be like this: if user input 2 and 3, program must display 2 + 3 = 5 part2 Write a function called add_numbers(n1, n2) that adds n1 and n2 display results in the function part3 Modify your program at part 2 that will return the result to the main program and display the result in the main program. Write a simple program In Java that asks the user to enter five test scores. The program should display a letter grade for each score and the average test score. Write the following functions in the program: Calc_averageThis function should accept five test scores as arguments and return the average of the scores. Determine_gradeThis function should accept a test score as an argument and return a letter grade for the score, based on the following grading scale. Soore 90-100 80-89 7079 6069 Below 60 Letter Grade A B D F