Question

Let the universal Set ,S have 121 elements. A and B are subsets of s. Set A contains 86 elements and Set b contains 26 elements. If sets A and B have 12 elements in common, How many elements are in A but not in B?

Answer 1

`\begin{gathered} Set\text{ A contains 86 elements} \\ Set\text{ B contains 26 elements} \\ 12\text{ elements in common} \\ x=\text{ elements are in A but not in B} \\ Set\text{ A= elements in common + x} \\ Solving\text{ x} \\ x=Set\text{ A-elements in common} \\ x=86-12 \\ x=74 \\ There\text{ are 74 elements in A but not in B} \end{gathered}`