12, 13, 14, 21, 31, 41: 6 if repetition is not allowed.
Sure. Any 1-digit number contains only one-digit numbers as factors. Any larger number, on the other hand, contains itself as a factor, so these can be excluded.
16000
5040 numbers can be made.
There are 9 x 10 x 10 x 10, or 9000 four-digit number that can be formed if the leading digit cannot be zero.
To determine how many digit numbers can be formed using the digits 2, 3, 5, 7, and 8, we need to consider the number of digits in the numbers we are forming. For a 1-digit number, we can use any of the 5 digits. For a 2-digit number, we can choose 2 out of the 5 digits and arrange them, giving us (5 \times 4) combinations. We can continue this for 3-digit, 4-digit, and 5-digit numbers, which will yield (5), (20), (60), and (120) respectively. Therefore, the total number of digit numbers is (5 + 20 + 60 + 120 = 205).
Sure. Any 1-digit number contains only one-digit numbers as factors. Any larger number, on the other hand, contains itself as a factor, so these can be excluded.
16000
Choose from 4 for the first number, 3 for the second number, and 2 for the third number. Therefore there are 4*3*2 = 24 three digit numbers can be formed from 3769 if each digit is used only once.
5040 numbers can be made.
Since both of those numbers contains four digits, there are no three-digit numbers between them.
There are 9 x 10 x 10 x 10, or 9000 four-digit number that can be formed if the leading digit cannot be zero.
3
There are 2000 such numbers.
Only four numbers:20233032
1339
It is 120 if the digits cannot be repeated.
write the number that is 500 more than the biggest number that can be formed by all the odd 1 digit number