Oh, dude, let me break it down for you. So, you've got 6 spots to fill with 6 different digits, right? That's like choosing from a buffet with only 6 items, easy peasy. So, you just raise 6 to the power of 6, which gives you 46,656 possible 6-digit numbers. Like, that's a lot of numbers, man.
125
There are 60480 numbers.
1 set
There are 4^6 = 4096 such numbers.
If the digits are all different then 18. Otherwise, 192.
Assuming the question refers to the digits 1, 2, ... , 9 the answer is 1344 numbers.
125
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
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
24
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
There are 60480 numbers.
1 set
It is 120 if the digits cannot be repeated.