Question

If $x:y=30:20$ and $y:z=24:25$ then the subduplicate ratio of $x:z$ is ____

• A. $6:5$
• B. $36:25$
• C. $5:6$
• D. $30:25$

Answer 1

The correct option is A $6:5$

$x:y=30:20$ and $y:z=24:25$
$\therefore \frac{x}{y}\times \frac{y}{z}=\frac{30}{20}\times \frac{24}{25}=\frac{36}{25}$
$\therefore x:z=36:25$
$\therefore$ The subduplicate ratio of $x:z$ is $\sqrt{36}:\sqrt{25}=6:5$