11111
There are 5 numbers which can make the 3 digit numbers in this example. Therefore each digit in the 3 digit number has 5 choices of which number can be placed there. Therefore number of 3 digit numbers = 5 x 5 x 5 = 125
12346
Not sure what a "didget" is. It is possible to make 18 5-digit numbers.
The first digit can be any one of 1,2,3,4,5. With each choice of digit1, the second digit can be any one of 1,2,3,4,5 so making 5*5 two-digit numbers. With each of these, the third digit can be any one of 1,2,3,4,5 so making 5*5*5 three-digit numbers and so on. The total number is 55 = 3125.
The smallest 5 digit number is 10000 = 1002 The largest 5 digit number is 99999 and 3162 < 99999 < 3172 So, take any number between 100 and 316 (both inclusive) and square it to get a 5-digit perfect square.
The question is a bit ambiguous: "the sum of the product ... " does not seem to make sense. The first 5 digit number is 10000 the first 5 digit multiple of 6 is 10002 Their product is 100020000. I am not sure what to sum, though.
00000 or 00001
99996
13,579 or .13579 . If I'm allowed to repeat digits, then you are 11,111 or .11111 .
The largest 5 all odd digit number is 99999, which makes the rest of the question meaningless. 59713 if you think the information is not meaningless
The digit in the tenths place in 10.51 is 5.