Explanation:
I assume we need to calculate the number of possible different results.
we don't know, if the sequence of the pulled objects matters or not.
in other words, when we have the 12 objects
a b c d e f g h i j k l
is e.g. the pulled result
a b c d e f g
the same as
g f e d c b a
?
or not ?
if they are the same, then we have combinations of 7 out of 12 objects :
C(12, 7) = 12! / ((7! × (12 - 7)!) =
= 12×11×10×9×8 / 5! = 3×11×2×3×4 = 792
if they are considered different results, then the order (or sequence) is important, and we have permutations of 7 out of 12 objects :
P(12, 7) = 12! / (12 - 7)! = 12! / 5! = 12×11×10×9×8×7×6 =
= 3,991,680