16 times
The question is incorrect since there are 210 - 1 possible combinations. The digit 0 can be in the combination or out. That gives 2 ways. With each, the digit 1 can be in the combination or out - 2*2 = 22 ways. With each, the digit 2 can be in the combination or out = 23 ways. With each, the digit 3 can be in the combination or out = 24 ways. etc. So 210 ways in all except that one of them is the null combination. Now 210 = 1024 so there are only 1023 combinations. If, instead, you allow the digits to be used many times, there is no limit to the number of combinations.
Only 1. In a combination, the order of the numbers does not matter. So 102478 is the same combination as 104782 or 407812 etc.
6,720 combinations.
10x9x9x9
There is only one combination. There are many permutations, though.
There are 126 different 5 digit combinations. Note that the combination 12345 is the same as the combination 45312.
You have a three digit number that can only use each digit once in combination. Therefore, a number like 456 is acceptable, but 455 or 101 or 222 is not acceptable. I think you can solve the problem in the following manner. There are 10 possible digits (0-9) that can be used in the first number. For the second number there are only 9 possible since you cannot repeat one of the first. For the third number there are only 8 possible since again you cannot repeat any of the first two. You multiply the possibilities for each digit to get our answer. 10 * 9 * 8 = 720 There are 720 possible combinations.
61
Using the eight digits, 1 - 8 ,-- There are 40,320 eight-digit permutations.-- There is 1 eight-digit combination.
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.
30.The first digit can be one of three digits {3, 6, 9} corresponding to the last digit being {1, 2, 3}, and for each of those three digits, the middle digit can be one of ten digits {0 - 9}, making 3 x 10 = 30 such numbers.It is assumed that a 3 digit number is a number in the range 100-999, excluding numbers starting with a leading zero, eg 090 is not considered a 3 digit number (though it would be a valid 3-digit number for a combination lock with 3 digits).
There are 9 digits that can be the first digit (1-9); for each of these there is 1 digit that can be the second digit (6); for each of these there are 10 digits that can be the third digit (0-9); for each of these there are 10 digits that can be the fourth digit (0-9). → number of numbers is 9 × 1 × 10 × 10 = 900 such numbers.
Just think of how many possibilities you have for each digit. 10x9x8x7x6x5x4x3x2 or 10 factorial is 3 628 800.
The first digit can be any one of the ten symbols, 0 thru 9. For each of those . . .The second digit can be any one of the 9 that weren't used in the first place. For each of those . . .The third digit can be any one of the 8 that you haven't used yet. For each of those . . .The fourth digit can be any one of the 7 that haven't been used yet.Total number of possible arrangements = (10 x 9 x 8 x 7) = 5,040
A decimal number is simply a way of representing a number in such a way that the place value of each digit is ten times that of the digit to its right. It is independent of a measurement unit.
Oh, dude, let me break it down for you. So, if you have 4 options for the first digit, 5 for the second, 6 for the third, and 7 for the fourth, you just multiply those numbers together. So, 4 x 5 x 6 x 7 equals 840 possible combination codes. Easy peasy, right?