Question

R is a relation from {11, 12, 13} to {8, 10, 12} defined by y = x – 3. The relation $R^{-1}$ is

• A. {(11, 8), (13, 10)}
• B. {(8, 11), (10, 13)}
• C. {(8, 11), (9, 12), (10, 13)}
• D. None of the above

Answer 1

The correct option is B {(8, 11), (10, 13)}

We have, R = {(x, y): y = x – 3, x = 11 or 12 or 13, y = 18
Or 10 or 12} = {(11, 8), (13, 10)}
$\therefore R^{-1}$ {(y,x) : (x,y) $ϵ$ R} = {(8,11), (10,13)}