04,14,24,34,40,41,42,43,44,45,46,47,48,49,54,64,74,84,94.... OR 19 Digits
There are 17 of them.
There is only one such number.
Let's count them out... 12 20 21 22 23 24 25 26 27 28 29 32 42 52 62 72 82 92 Whew... that makes 18 two-digit numbers that have a "2".
There are 21 two-digit prime numbers.
1000there aren't even 1000 three-digitnumbers...There are the digits 1 through 9 for the first digit. Then, we have 0 through 9 for the second digit - excluding the first digit. For the third digit, we have 0 through 9, excluding the two previous digits for a total of 9*9*8 =81*8 =648 three digit numbers with distinct digits.EDIT- ... to be a little more specific, if your talking about a 3-digit password or unlock code its would be 1000. _-_
There are 6804 such numbers.
27: 077,177,277,377,477,577,677,877,977,717,727,737,747,757,767,777,787,797
04,14,24,34,40,41,42,43,44,45,46,47,48,49,54,64,74,84,94.... OR 19 Digits
There are 90 two digit numbers, 10 through 99. There are 18 two digit numbers containing a 9. They are 19, 29, 39, 49, 59, 69, 79, 89, and 90 through 99. Therefore, there are 72 two digit numbers that do not contain a 9.
There are 17 of them.
There is only one such number.
18 positive integers and 36 integers (negative and positive)
greatest two digit number is 99. smallest whole number is 0 there fore 99-0=99
Let's count them out... 12 20 21 22 23 24 25 26 27 28 29 32 42 52 62 72 82 92 Whew... that makes 18 two-digit numbers that have a "2".
There are 21 two-digit prime numbers.
36