-123456786
There are 504 such numbers.
To form a two-digit odd number using the digits 123456789 without repetition, the unit's digit must be an odd number. The available odd digits are 1, 3, 5, 7, and 9, giving us 5 options for the unit's place. For the ten's place, we can choose any of the remaining 8 digits. Therefore, the total number of two-digit odd numbers is (5 \times 8 = 40).
99999
There are 5 numbers of 1 digit, 25 numbers of 2 digits, and 75 numbers of 3 digits. This makes 105 numbers in all.
500
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
There are 3024 of them.
There are 60480 numbers.
There are 504 such numbers.
99999
There are 5 numbers of 1 digit, 25 numbers of 2 digits, and 75 numbers of 3 digits. This makes 105 numbers in all.
24
500
Numbers formed should be of at least 3 digits means they may be of 3 digits, 4 digits, 5 digits or 6 digits. There are 6 choices for digit in the units place. There are 5 and 4 choices for digits in ten and hundred’s place respectively. So, total number of ways by which 3 digits numbers can be formed = 6.5.4 = 120 Similarly, the total no.of ways by which 4 digits numbers can be formed = 6.5.4.3 = 360. the total no. of ways by which 5 digits numbers can be formed = 6.5.4.3.2 = 720. The total no.of ways by which 4 digits numbers can be formed = 6.5.4.3.2.1 = 720. So, total no.of ways by which the numbers of at least 3 digits can be formed = 120 + 360 + 720 + 720 = 1920.
840
1 set
It is 120 if the digits cannot be repeated.