How many combinations are possible using the numbers 4 specific numbers?

Answer 1

the question does not make sense, as it stands.

if the 4 refers to the idea of providing 4 specific numbers and then combining them in different ways

there are lots of combinations such as adding them or multiplying them, etc., but.....

if you mean combining the numbers by listing all 4 of them in different orders, that's called permutation, not combination. How many ways? Well, there are 4 ways of choosing which one comes first, then three choices for the next and two for the next, so you have 24 ways.

If you are interested in combinations of numbers that's different. you my wish to select just one , two, three or all 4 of a set of numbers.

If the order didn't matter, there is 1 way of selecting none of them, 4 ways of only choosing one, and six ways of choosing only 2, 4 ways of choosing three,1 way of choosing all 4. that's 16 combinations.

If the order matters, you have to permute each of your combinations. 65 possible results!