For instance, if the number contains no 9s, the tenth digit must be 0. That means our number will inevitably have plenty of zeros. It also likely won’t include many high numerals, because the digits are limited. You’ll have to test several possibilities.
This is the toughest puzzle in the book, and based on your performance so far, you’ve got better odds of winning the lottery than solving it. If you insist on trying, instead of buying a ticket, start by testing the first digit. For example, if you set the first digit to 6, it means the number begins with 6 and will contain six zeros. Figure out where those six zeros could possible set so that all the other conditions are satisfied at the same time.