If P and Q are two sets such that P∪Q has 40 elements, P has 22 elements and Q has 28 elements, How many does P∩Q have?
If P and Q are two sets such that P has 40 elements, P∪Q has 60 elements and P∩Q has 10 elements, how many elements does Q have ?
If X and Y are two sets such that X∪Y has 50 elements,H has 28 elements and Y has 32 elements,how many elements does X∩Y have?
If set A has p elements and set B has q elements, number of elements in set (A × B) is _____.