Question

If $p$ varies inversely as $q$, and $p=7$ when $q=3$, find $p$ when $q=2\frac{1}{3}$.

Answer 1

As $p$ varies inversely as $q$ then let,

$p=\frac{k}{q}$, where $k$ is a constant

As $p=7$ and $q=3$ satisfies so,

$7=\frac{k}{3}$

$k=21$

$\therefore p=\frac{21}{q}$

For $q=\frac{7}{3}$

$p=\frac{21}{\frac{7}{3}}=3\times 3=9$