Q. Let $A = \{ x,\ y,\ z\}$ and $B = \{ a,\ b,\ c,\ d\}$. Which one of the following is not a relation from $A$ to $B$?
A) $\{(x,\ a),\ (x,\ c)\}$
B) $\{(y,c),\ (y,\ d)\}$
C) $\{(z,a),\ (z,\ d)\}$
D) $\{(z,\ b),\ (y,\ b),\ (a,\ d)\}$
Explanation
(d)
$\{(z,\ b),\ (y,\ b),\ (a,\ d)\}$ is not a relation from $A$ to $B$ because $a \notin A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.