If S is a set with 10 elements and A={(x,y):x,y∈S,x≡y}, then the number of elements in A is
100
90
50
45
Explanation for the correct option.
Given the number of elements in S=10and A={(x,y):x,y∈S,x≡y}Then, the number of elements in A is given by:
∴A=10×9=90.Hence, option B is correct.
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