The smallest such number is 100, the largest is 999, so the size of this set is:999 - 100 + 1
Another way to solve this: You have:
* 9 options for the first digit
* 10 options for the second digit
* 10 options for the third digit
Multiply all these numbers together.
525
120 There are 6 digits in total. The numbers with 3 digits, with all digits distinct from each other, are the permutations of the 6 digits taken 3 at a time, and therefore there are 6*5*4 = 120 of them.
There are exactly 320 pages in 852 digits.
There are 167960 9 digits combinations between numbers 1 and 20.
36
890
how many numbers exactly have 4 digits ? 8900, 8999, 9000, 9999
98,764
All numbers are made with digits and there is no limit on how big they can be. So there is no greatest number.
90 of them.
There are 90 of them.
900
900000
90000 of them.
there are 89 twodigits in whole numbers
Assuming that 001, 080, etc are not allowed (that is a leading zero or two is not permitted), the smallest number with exactly three digits is 100. The largest number with exactly three digits is 999. So there are 999 - 100 + 1 = 900 numbers with exactly three digits.
90