Question

Let R be a relation from A {1, 2, 3, 4) to B (1, 3, 5) such that `R{ (a, b):a < b, `where `a in A and b in B)` then what is `ROR^(-1)` equal to?
A. {(1,3),(1,5),(2,3),(2,5),(3,5),(4,5)}
B. {(3,1),(5,1),(3,2),(5,2),(5,3),(5,4)}
C. {(3,3),(3,5),(5,3),(5,5)}`
D. {(3,3),(3,4),(4,5)}

Answer 1

Correct Answer - C
`R={(1,3),(1,5),(2,3),(2,5),(3,5),(4,5)}`
`implies R^(-1)={(3,1),(5,1),(3,2),(5,2),(5,3),(5,4)}`
`implies RoR^(-1)={(3,3),(3,5),(5,3),(5,5)}`.