Yuo can make only one combination of 30 digits using 30 digits.
456, 546 and 564 are three of the four possible even numbers.
2,357,896
200992
8643
531
97632 is the largest number containing these digits. To make the largest number simply order the numbers in descending order. As it happens this results in an even number so nothing further is necessary.
987654321
It is 4579.
98765.
8642
Using only positive digits, and disregarding their order, 3 ways.