If

Question:

If $A=\{3,5,7\}$ and $B=\{2,4,9\}$ and $R$ is a relation given by "is less than", write $R$ as a set ordered pairs.

Solution:

Since, $R=\{(x, y): x, y \in N$ and $x$\mathrm{R}=\{(3,4),(3,9),(5,9),(7,9)\}\$