i need this program solution in java

Exercise 1: Using Input and Output Statement Write a program that inputs three integers from the user. Then your program should calculate the sum, and average. Display all the results. Exercise 2: Using Input and Output Statement Write a program that will ask user's age. It will display "young" if the age is less than 20 or else will display "adult Exercise 3: Write a program that can accept 3 numbers and display the smaller to screen. Exercise 4: Write a java application to print the factorial of given number. The factorial of a non-negative integer n, denoted by nl, is the product of all positive integers less than or equal to n. For example, 5! - 5 X 4 X 3 X 2 X 1 = 120. Post-Exercise 1: Write a program, which ask you to enter your weight and height and tells you about your BMI. Body Mass Index (BMI) is a measure of health on weight. It can be calculated by taking your weight in kilograms and dividing by the square of your height in meters. The interpretation of BMI is as follows