Question

If \(a \epsilon {2, 4, 6, 9} and \(b \epsilon \{4, 6, 18, 27\}, then form the set of all ordered pairs (a, b) such that a divides b and a < b.

Answer 1

We have,

$aϵ\{2,4,6,9\}$

and, $bϵ\{4,6,18,27\}$

Now, $\frac{a}{b}$ stands for 'a divides b'. For the elements of the given sets, we find that $\frac{2}{4},\frac{2}{6},\frac{2}{18},\frac{6}{18},\frac{9}{18},\frac{9}{27}$ are the required set of ordered pairs (a, b).

$\therefore \left\{\right(2,4),(2,6),(2,18),(9,18),(9,27\left)\right\}$ are the required set of ordered pairs (a, b).