9:06 But wait -32 and 10 were the answers to the counting questions about subsets. Coincidence? Not at all. Each bit string can be thought of as a code for a subset. To represent the subsets of A = { 1 , 2 , 3 , 4 , 5 } , we can use 5-bit strings, one bit for each element of A . Each bit in the string is a 0 if its corresponding element of A is not in the subset, and a 1 if the element of A is in the subset. Remember, deciding the subset amounted to a sequence of five yes/no votes for the elements of A . Instead of yes, we put a 1; instead of no, we put a 0.
