How many combinations are there in 4 numbers?

10

* * * * *

That is just plain wrong!

It depends on how many numbers in each combination but there are

1 combination of 4 numbers out of 4,

4 combinations of 3 numbers out of 4, 6 combinations of 2 numbers out of 4,

4 combinations of 1 number out of 4.

A grand total of 15 (= 24-1) combinations.