Let R, S, and T be subsets of the universal set U. Draw an appropriate Venn diagram, and use the given data to determine the number of elements in each basic region.
1. n (U) = 17, n (S) = 12, n (T) = 7, n (S ∩ T ) = 5
2. n (U) = 20, n (S) = 11, n (T) = 7, n (S ∩ T ) = 7