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.

Answer 1

$$\begin{gathered} \mathrm{Since},R=\left\{\left(x,y\right):x,y\in N\mathrm{and}x<y\right\}, \\ \mathrm{R\; =\; \{(3,}\mathrm{4),}(3,9),(5,9),(7,9)\} \end{gathered}$$