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Question 12 Equivalence relations are relations for which it is possible to see related elements as "similar" in some or other sense. Decide for each of the following relations whether or not it is an equivalence relation. Give full reasons. If it is an equivalence relation, give the equivalence classes. (a) Let a and b be integers. Define aRb if and only if the product of a and bis even. (b) Let a and b be sets of natural numbers. Define aRbif and only if a and b are disjoint, that is anb=0. (c) Let A=R (the real numbers). Define aRb if and only if a - bis an integer.