# Suppose f varies inversely with g and that f = 45 when g = 6 . What is the value of f when g = 9?

May 31, 2016

$30$

#### Explanation:

Given
$f \propto \frac{1}{g}$
or ${f}_{1} . {g}_{1} = {f}_{2} . {g}_{2}$ ......(1)
Let the required value of $f = x$
Inserting in equation (1)
$45 \times 6 = x \times 9$
Solving for $x$
$x = \frac{{\cancel{45}}^{5} \times 6}{\cancel{9}} _ 1 = 30$