Question

Find the value of $x$ for which the following forms a proportion:
$7:14=15:x$

Answer 1

Given that : $7:14=15:x$

$\Rightarrow \frac{7}{14}=\frac{15}{x}$

$\Rightarrow 7\times x=15\times 14$

$\Rightarrow x=15\times \frac{14}{7}=15\times 2=30$

$\Rightarrow x=30$