100,000
12
24
There are 504 such numbers.
823543
13579
As there are 5 different digits, allowing for repetition of a digit, the first digit can be any of the 5, and for each of these, the second can be any of the 5, and so for the third, making: 5 x 5 x 5 = 125 different 3-digit numbers.
9999
100,000
12
512
24
There are 504 such numbers.
There are 60480 numbers.
840
823543
6