If X and Y are two sets such that X has 40 elements, X Y has 60 elements and X Y has 10 elements, how many elements does Y have?


Given-


n(X) = 40, n(X Y) = 10, and n(X Y) = 60


We know that-


n(X Y) = n(X)+ n(Y) - n(X Y)


60 = 40+n(Y) - 10


60 = 30+n(Y)


n(Y) = 60-30


n(Y) = 30


Thus, the no. of elements in n(Y) is 30.


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