Question

$x:5a38c15$

$y:241040b20d$; $x$ and $y$ are proportional. Find the value of $b$

• A. $10$
• B. $24$
• C. $12$
• D. $15$

Answer 1

The correct option is D $15$

$xy=5\times 24=3\times 40=120=k$

$\Rightarrow x$ is inversely proportional to $y$. [because product is constant]

$\Rightarrow 5\times 24=10a=3\times 40=8b=20c=15d=120$

$\Rightarrow b=\frac{120}{8}=15$