Question 438729: without writing them all out, what is the number of subsets of set A=(king,queen,knight,prince,princess,duke,earl)? I see that everybody is talking about 2n or something like that can you explain the answer step by step please?
Answer by richard1234(7193)   (Show Source):
You can put this solution on YOUR website! For each element, we can either choose that element to be included in the subset, or we can exclude it. There are 2 choices for each element, and n elements (in this case n = 7), so 2^7 = 128 ways.
You can also try small cases (e.g. n = 1, n = 2), and notice and prove that the pattern holds.
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