Answer
$E=0.857$
Here, $E<1$ meaning, that the demand is inelastic to the price change.
Work Step by Step
If the demand function is $q=(100-p)^2$ and $p=\$30$
The elasticity can be calculated as:
$E=-\frac{dq}{dp}\times\frac{p}{q}$
The derivative of the demand function is :$\frac{dq}{dp}=-2(100-p)$
Therefore at the given price $E=-(-2(100-30))\times\frac{30}{(100-30)^2}=0.857$
Here, $E<1$ meaning, that the demand is inelastic to the price change.
