qqp question1: "How did the "" _ + _ + _ = 30 using 1, 3, 5, 7, 9, 11, 13 and 15"" riddle become so popular?" question2: How many 6 digit number can be formed by using the digits 0,1,2,3,4,5,6,7,8. If every number is to start with 30 with no digit repeated?