Question

Find $x$ in the following proportions:
$\frac{1}{13}:x::\frac{1}{2}:\frac{1}{5}$

Answer 1

$\frac{1}{13}:x::\frac{1}{2}:\frac{1}{5}$
By cross product rule
Product of means $=$ Product of extreme
$x\times \frac{1}{2}=\frac{1}{13}\times \frac{1}{5}$
$x\times \frac{1}{2}=\frac{1}{65}$
$x=\frac{1}{65}÷\frac{1}{2}$
$x=\frac{1}{65}\times 2$
$x=\frac{2}{65}$