3 digit numbers are lessthan 4 digit numbers
A 3 or 4 digit number.
There is no such ratio that applies for all single-digit and double-digit integers.
It would probably be most appropriate to spell out the number. Example: Three hundred years later...
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.
44 for example should be written forty four.
3 digit numbers are lessthan 4 digit numbers
The answer will depend on how many digits there are in each of the 30 numbers. If the 30 numbers are all 6-digit numbers then the answer is NONE! If the 30 numbers are the first 30 counting numbers then there are 126 combinations of five 1-digit numbers, 1764 combinations of three 1-digit numbers and one 2-digit number, and 1710 combinations of one 1-digit number and two 2-digit numbers. That makes a total of 3600 5-digit combinations.
A 3 or 4 digit number.
There is no such ratio that applies for all single-digit and double-digit integers.
There are 28706 such combinations. 5456 of these comprise three 2-digit numbers, 19008 comprise two 2-digit numbers and two 1-digit numbers, 4158 comprise one 2-digit number and four 1-digit numbers and 84 comprise six 1-digit numbers.
With a total of 90,000 five digit numbers, we can conclude that there is 45,000 EVEN five digit numbers.
Oh, what a lovely question! If we're looking for 2-digit numbers where the one's digit is greater than the ten's digit, we simply need to think about the possibilities. There are 36 such numbers, ranging from 12 to 98. Just imagine all the happy little numbers waiting to be discovered!
Digit.
There are 9 1-digit numbers and 16-2 digit numbers. So a 5 digit combination is obtained as:Five 1-digit numbers and no 2-digit numbers: 126 combinationsThree 1-digit numbers and one 2-digit number: 1344 combinationsOne 1-digit numbers and two 2-digit numbers: 1080 combinationsThat makes a total of 2550 combinations. This scheme does not differentiate between {13, 24, 5} and {1, 2, 3, 4, 5}. Adjusting for that would complicate the calculation considerably and reduce the number of combinations.
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.
Using the digits of 1345678, there are 210 three digit numbers in which no digit is repeated.