java

and please explain how to make the .java file

Convert the following problems you have learned in your term1 into Java programs: 1- calculating the miles per gallons- assign values to two vars: miles and gallons, then calculate the mpg = miles times gallons, then print the value of mpg. 2- calculating the employee's net pay- assign values to these vars: hours worked, days worked, pay rate and tax percent. Then calculate the gross pay: hours times days times pay rate, then the net pay is gross pay minus the amount of tax, then print out the employee name and the net pay