Need help on these 3 problems in Java. Please be specific in coding for solutions so that I can understand.

1. An integer is input through the keyboard. Write a program to find out whether it is an odd number or even number.

2. A year is input through the keyboard. Write a program to determine whether the year is a leap year or not.

3. If the ages of 3 persons are input through the keyboard, write a program to determine the youngest of the three.