Question

Of all the nonempty subsets s of { 1, 2, 3, 4, 5, 6, 7}, how many do not contain the number |s|, where |s| denotes the number of elements in s? For example, {3, 4} is one such subset, since it does not contain the number 2. Please do not add white space around the answer ____________

Answer 1

Answer:

1,2,3,4,5,(1,2),(1,3),(1,4),(1,5),(2,3),(2,4),(2,5),(3,4),(3,5),(4,5),(1,2,3,4,5)