We have to assume we can use each digit only once else our number would be infinitely long. The digits that are multiples of 3 are 0 (3 * 0), 3 (3 * 1), 6 (3 * 2) and 9 (3 * 3).
We simply need to order these in descending order then:
9630
You get the largest number if you sort the digits, from largest to smallest.
99
If the digits are only used once, each, the largest possible number would be 97,531
The largest odd number that can be made with those digits is 9407 .
the largest five digit number that can be formed using the digits 7 and 9 is 97,000
You get the largest number if you sort the digits, from largest to smallest.
543,210. If you can use them all multiple times, then it is 555,555.
Using the digits 12279, the largest number that can be represented is 97,221.
7654321
97432
99
If the digits are only used once, each, the largest possible number would be 97,531
The largest even number that can be made with those digits is 9740 .
The largest odd number that can be made with those digits is 9407 .
the largest five digit number that can be formed using the digits 7 and 9 is 97,000
543210
985,316