'A' is a set containing n elements. A subset 'P' of 'A' is

Last updated: 7/12/2022

'A' is a set containing n elements. A subset 'P' of 'A' is chosen. The set 'A' is reconstructed by replacing the elements of 'P', A subset 'Q' of 'A' is again chosen. The number of ways of choosing 'P' and 'Q', so that PnQ contains exactly two elements is A B D 9¹C₂ 3- "C₂ 2¹C₁ none of these