Suppose Set A contains 10 elements and the total number elements in either Set A or Set B is 56. If the Sets A and B have 7 elements in common, how many elements are contained in set B?

Answer 1

draw a Venn diagram

A and B overlap with 7 elements

B has 46 elements not in A, 46 + 10 = 56 elements in A or B

B has 46 + 7 = 53 elements