Question

If A = { 1, 2, 3, 4, 5, 4, 9, 11g find n CA)​

Answer 1

Let A = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} . Then the number of subsets of A containing exactly two elements is

Missing: 11g ‎| Must include: 11g

Number of elements in A = 10 Number of subsets of A containing exactly two elements = Number of ways we can select 2 elements from 10 elements ^10C2 = ...