1、three positive integers(正整数)have a sum of 28.The greatest

1、three positive integers(正整数)have a sum of 28.The greatest possible product that these integers can have is_______.
2、two numbers are in the ratio 2:3.when 4 is added to each number the ratio changes to 5:7.The sum of two orginal numbers is______.
3、Did you know?A palindrome is a number(回文数）which reads the samn forwards as backwards e.g.(例如)35453.Next year 2002 is an exanple of a palindrome number.What are the difference between 2002 and the number od the previous(以前)palindrome year?