How do you figure out all possible 4 diget number combinations?

Question

Using 1, 2, 3, 4, 5, 6, 7, 8, 9, 0

Answer 1

10 x 10 x 10 x 10 = 10,000

In each multiple, you put the # of possibilities. Since there are 10 digits and 4 slots you would do 10 to the 4th power.

If you were not allowed to repeat a digit then:

10 x 9 x 8 x 7 = 5,040.


* Since there is no RULE in your statement about a zero being on the left, you can use 10 in the first slot. Who's to say these aren't lock combinations?

Answer 2

Using the multiplication rule and a little of analization, we will find out how many 4 digit numbers can be formed from your numbers.

for the thousands, we will use numbers 1 2 3 4 5 6 7 8 and 9 since 0 will be not significant and making the number a 3 digit number.

For the other digits, since it is not indicated that repetition is not allowed, we can use all the 10 digits.

So from the law of multiplication, 9*10*10*10 = 9 000

Answer 3

Start with 0001 and add 1 resulting in 0002. Continue adding one until the next number would be a 5 digit number., However since your question asked about combinations, it is important to know more details. Is the order of the digits taken into consideration? If so, for example, 1234 would be different from 4321. If you are looking for unique combinations, then these two would be considered the same, along with other combinations such as 3412, 2341, 2413, 2431, and others. Also, can a digit be used more than once? If not, the numbers such as 2222, 3344, and any other numbers with a repeating digit would have to be eliminated. Right away, this gets rid of the numbers 0001 through 0122. 0123 would e the first valid number. If order does not matter, and each digit can only be used once then the formula for mathematical combinations can be used, and there would be 4! (four factorial) distinct combinations or 4x3x2x1=24 possibilities.

Answer 4

Lol
I can't quite believe people are putting down numbers with 5 digits.
The first 4 digit number is 1000 and the last one is 9999.
Therefore there is 9000 combinations of 4 numbers.heres my working out:
9999-999=9000.
999 is the last 3 digit number so this is why the answer is a round number and not 1 less (because 1000 is counted as the first and not 1001)

Answer 5

Reasoning 10 numbers combining 4 each time. The order of the numbers is not important, so that 0123 is same as 0132 or John Doe =Doe John, and so on.
Use 10 Combination 4:
10C410!/(6! x 4!)= 10x9x8x7x6!/(6!x4x3x2x1) = 210

Answer 6

Can you reuse a number? if no then you have 10 possible first numbers 9 second 8 third and 7 fourth 10x9x8x7= possible combinations. If yes then 10x10x10x10= a lot of numbers

Answer 7

starting from 1000 to 9999.
means 9999-1000+1 (because we also include 1000 as anwer) =9000
or use probability 9*10*10*10 =9000
remember, the first digit cannot be 0

Answer 8

all ten numbers are multiplied by the power of the number of combo digits in this case 4

ten to the power of 4 is 10000 possible combinations

Answer 9

The answers 10000 (allowing for repeats) and 5040 (not allowing for repeats) given above are correct given that order matters. But accounting for the possibility that order doesn't matter (which would mean no repeats), the answer would be 10!/(4! * 6!) = 210

Answer 10

9*10*10*10=9000
the first digit can be any but 0 , rest all can be any of the 10. Use Permutaion