Question

If $x$ is in direct proportion to $y$ and at $x=10$, $y=5$, then the constant of proportionality is

• A. 2
• B. 1
• C. 5

Answer 1

The correct option is A 2

Here, $x$ is in direct proportion to $y$.
Let $K$ be the constant of proportionality.
$\Rightarrow x=Ky$
At, $x=10,y=5$
$\therefore 10=K\times 5\Rightarrow K=2$
Hence, $K=2$ is the constant of proportionality.