Let X = {1, 2, 3, 4, 5} and Y = {1, 3, 5, 7, 9}. Which of the following is(are) relation from X to y ?
Answer & explanation
Correct answer: option 2
$R_1$ (Not a relation) from X → Y
as $x,y∈y$ and $x∉ X$
$R_3$ (Not a relation)
as (1, 1) and (1, 3) $∈R_3$
two image of one preimage not allowed
$R_4$ is not a relation from X to Y
as $(7, 9)∉ X$