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Define binary operations on sets?

Important Questions on Set Theory and Relations

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Consider the following relations in the real numbers R1=(x,y)x2+y225 and R2=(x,y),y4x29, then the range of R1R2 is
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Let N denote the set of all natural numbers. Define two binary relations on N as R1=x,yN×N:2x+y=10 and R2=x,yN×N:x+2y=10. Then
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If n(A)=2 and total number of possible relations from set A to set B is 1024, then n(B) is
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If there are 2 elements in a set A, then what would be the number of possible relations from the set A to set A?
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If A=a,b,c, then the number of binary operations on A is
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Let A,B,C are three non-empty sets. The number of relations from A to B is 64, that of B to C is 4096 and that of A to C is 256. Then the numbers of elements of the sets are in
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If R=x, y:x, yZ, x2+3y28 is a relation on the set of integers Z, then the domain of R-1 is
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Let  be a binary opertation on -0 defined by a b=ab. Then 1234 is equal to
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Let* be a binary operation on the set R of real numbers defined by a*b=3ab7, then the identity element in R for * is
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The number of binary operations on the set {1, 2, 3} is
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Let A=0,3,4,6,7,8,9,10 and R be the relation defined on A such that Rx,yA×A:x-y is odd positive integer or x-y=2. The minimum number of elements that must be added to the relation R, so that it is a symmetric relation, is equal to _________
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For the binary operation * defined on R1 by the rule a*b=a+b+ab for all a, bR1, the inverse of a is
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Let A=2,3,4 and B=8,9,12. Then the number of elements in the relation  R=a1,b1,a2,b2A×B,A×B:a1 divides b2 and a2 divides b1 is
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Let A be a set consisting of 10 elements. The number of non-empty relations from A to A that are reflexive but not symmetric is
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Among the two statements

S1:pqp~q is a contradiction and S2:pq~pqp~q~p~q is a tautology

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Define identity element for a binary operation defined on a set.
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The identity element of the binary operation * on R defined by a*b=ab4 a,bR is
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Let * be a binary operation on the set R, of all real numbers defined by 5a*b=ab, for all a,bR. The inverse of 0.5 under the operation * is
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If * is a binary operation defined by a*b=ab+ba+1ab for positive integers a and b, then 2*5 is equal to
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On the set of positive rationals, a binary operation * is defined by a*b=2ab5. If 2*x=3-1 then x=