If a relation R is defined from a set A = {2, 3, 4, 5} to a set B = {3, 6, 7, 10} as follows (x,y)∈R⇔x divides y. Expression of R-1 is represented by
(3)
Recall that a∣b stands for a divides b. For the elements of the given sets A and B, we find 2∣6, 2∣10, 3∣3, 3∣6, 5∣10
⇒ R={(2,6),(2,10),(3,3),(3,6),(5,10)}
∴ R-1={(6,2),(10,2),(3,3),(6,3),(10,5)}