Let S={1, 2, 3....................20}, `R_1` = {(a, b) : a divides b}, `R_2` ={(a,b):a is integral multiple of b} and `a, b in S`, then `n(R_1-R_2)=?`

Let A= {1, 2, 3, . . 20} . Let R_1 and R_2 two relation on A such that R_1 = {(a, b) : b is divisible by a} R_2 = {(a, b) : a is an integral multiple of b}. Then, number of elements in R_1 – R_2 is equal to ________.

Let R be the relation in the set N given by R = {a,b):a is a multiple of b} .Then :

If R = {(a,b) : a+b=4} is a relation on {1,2,3} , then R is

Let ={1,2,3,4} adn R={(a,b):a in A,b in A,a divides b}. Write R explicity.

Let A = {1, 2, 3} and R = {(a,b): a,b in A, a divides b and b divides a}. Show that R is an identity relation on A.

If A ={ 1, 2, 3,. . . , 10} R : A to A R = { (a, b) : | a - b| is a multiple of 3} is an equivalence relation, then the equivalence class [1] is

Let A={1, 5), B={3, 7) and R={(a, b) :a in A, b in B and a-b is a multiple of 4}. Show that R is an empty relation from A to B.

Let R_1={(a,b)inRtimesR:a^2+b^2=1} "and" R_2={(a,b)R(c,d) such that a+d=b+c } are two relations then

If relation R_1={(a,b):a,b in R,a^2+b^2 in Q} and R_2={(a,b):a,b in R, a^2+b^2 !in Q} Then

Let R_(1) be a relation defined by R_(1)={(a,b)|agtb,a,b in R} . Then R_(1) , is