The correct options are
A R−1={(x,y):x,y∈N,x>y,x+y=7
B Domain of R can be {1,2,3,5}
C Range of R can be {3,5,7}
D Co domain of R is {3,4,5,6,7}
If x,y∈N,x>y,x+y=7
x=6,y=1⇒(x,y)=(6,1)
x=5,y=2⇒(x,y)=(5,2)
x=4,y=3⇒(x,y)=(4,3)
Here, B×A={(3,1),(3,2),(4,3),(5,2),(7,5),(6,1)}
and R−1⊂B×A
Domain can be the first element of ordered pair from A×B
∴ Domain of R can be {1,2,3,5}
Range can be the second element of ordered pair from A×B
∴ Range of R can be {3,5,7}
Co domain is set of all the second elements of ordered pair from A×B
∴ Co domain of R is {3,4,5,6,7}