How many different 6-digit combinations can 0123456789 form
If the six numbers of six digits are different, it is 9 * 9 * 8 * 7 * 6 * 5 = 136080
It can be the same as 999999-100000 + 1 = 900000
If the six numbers of six digits are different, it is 9 * 9 * 8 * 7 * 6 * 5 = 136080
It can be the same as 999999-100000 + 1 = 900000