# Let

Question:

Let $A=\{3,5,7\}, B=\{2,6,10\}$ and $R$ be a relation from $A$ to $B$ defined by $R=\{(x, y): x$ and $y$ are relatively prime $\}$. Then, write $R$ and $R^{-1}$.

Solution:

R = {(xy) : x and y are relatively prime}
Then,

R = {(3, 2), (5, 2), (7, 2), (3, 10), (7, 10), (5, 6), (7, 6)}

So, $R^{-1}=\{(2,3),(2,5),(2,7),(10,3),(10,7),(6,5),(6,7)\}$