The number of possible combinations of 4 numbers depends on the context whether repetition is allowed and whether order matters:
- If order matters and repetition of digits is allowed (like a 4-digit PIN code), there are 104=10,00010^4=10,000104=10,000 possible combinations because each of the 4 positions can be any of the 10 digits (0-9).
- If order matters but digits cannot repeat, the number of permutations is 10×9×8×7=504010\times 9\times 8\times 7=504010×9×8×7=5040.
- If order does not matter and digits do not repeat, the number of combinations of 4 digits chosen from 10 is 10×9×8×74×3×2×1=210\frac{10\times 9\times 8\times 7}{4\times 3\times 2\times 1}=2104×3×2×110×9×8×7=210.
- For just 4 distinct numbers arranged in all possible orders (permutations), there are 4!=244!=244!=24 combinations.
So the exact number depends on the rules applied to the selection of 4 numbers. If the question is about any 4-digit number from 0000 to 9999, there are 10,000 possible combinations.
