A subset of A is an array (or whatever kind of data structure A is) that contains only elements of A. For example, if A is [0, 1, 2, 3, 4, 5, 6, 7, 8, 9], then one possible subset would be [0, 1, 2] or [5, 6, 7, 8, 9]. Assuming order doesn't matter, you need to find the possible combinations of A's elements (assuming they're all distinct from each other) in groups of 1, 2, 3, 4, and so on up to all ten elements. In the second part, you'll be using just groups of 1, and in the third part, subtract the second answer from the first one. If there's an nCr button on your calculator, you can use this to find these numbers.

The nCr function, or C(n, r), finds the number of combinations (C) of n things in groups of size r. If you want to do it by hand, the function is n! / (r! (n - r)!).

Part 1 = C(10, 1) + C(10, 2) + C(10, 3) + C(10, 4) + C(10, 5) + C(10, 6) + C(10, 7) + C(10, 8) + C(10, 9) + 1

Part 2 = C(10, 1)

Part 3 = Part 1 - Part 2

i would really like it if someone could help explain it to me, thankyou.

-Find the number of subsets of A having one or more elements

-Find the number of subsets of A having exactly one element

-Find the number of subsets of A having two or more elements

Thankyou....so lost right now