Question

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

• A. $\{(8,11),(10,13)\}$
• B. $\{(11,8),(13,10)\}$
• C. $\{(10,13),(8,11)(8,10)\}$
• D. none of these

Answer 1

Answer: (A)

$\{(8,11),(10,13)\}$

First let's write R,

$R=\left\{\right(11,8),(13,10\left)\right\}$

So, $R^{-1}=\left\{\right(8,11),(10,13\left)\right\}$