The cardinal number of a set can be said to be the number of distinct elements in a finite set.
Here, we have the number: 2,309,585,628.
We have the following elements:
2
3
0
9
5
8
6
Some elements occured twice here, no element is to be counted twice.
Thus,
Set Q = {2, 3, 0, 9, 5, 8, 5, 6, 2, 8}
The set Q has 7 elements
The cardinal number of set Q is 7
ANSWER:
n(Q) = 7