The Venn diagram here shows the cardinality of each set. Use this to find the cardinality of given set.

[Graphs generated by this script: initPicture(-5.5,5.5,-5.5,5.5);fill='transred';circle([0,-1.7],3);fill='transgreen';circle([2,2],3);fill='transblue';circle([-2,2],3);fontbackground='white';text([-3,3],'12');text([3,3],'14');text([0,-2.8],'15');text([0,2.2],'9');text([-1.5,-.2],'4');text([1.5,-.2],'5');text([0,.6],'3');text([4.5,-4.5],'3');text([-4.5,4.5],'A');text([4.5,4.5],'B');text([-2.2,-4.5],'C');]

$\displaystyle {n}{\left({A}\right)}$ =

$\displaystyle {n}{\left({A}\cap{C}\right)}$ =

$\displaystyle {n}{\left({A}\cap{B}\cap{C}^{{c}}\right)}$ =