# From 1 to 9

**Discrete Mathematics**Level 3

In how many ways you can arrange numbers 1,2,3,4,5,6,7,8,9 in a row, so that the numbers 1,2,3,4,5,6,7 appear in that order; but instead, the numbers 1,2,3,4,5,6,7,8,9 not appear in that order? (One way to arrange the numbers 1,2,3,4,5,6,7,8,9 so that the required conditions are met is 129384567)