Question

If A = {3, 4, 7, 8} and B = {1, 7, 10} then, the relation R = holds relations from A to B.

• A. {(8,10)}
• B. {(3,1), (4,12)}
• C. {(81,1), (64,12)}

Answer 1

The correct option is A {(8,10)}

Given, A = {3,4,7,8} and B = {1,7,10}
$\therefore$ Cartesian Product of A and B is
A $\times$ B = {(3,1), (3,7), (3,10), (4,1), (4,7), (4,10), (7,1), (7,7), (7,10), (8,1), (8,7), (8,10)}
Now,
{(8,10)} $\subseteq$ A $\times$ B. Thus, R = {(8,10)} is a relation from A to B.
But {(3,1), (4,12)} and {(81,1), (64,12)} is not a $\subset$ of $A\times B$.