Answer
$P(Z \lt 30)$ should be considered as $\lt 0.0001$
Note that we should not round to "0", since this could give someone the impression that the event is not possible (i.e. will never occur).
Work Step by Step
First we need to calculate the z score:
$z = \frac{x - μ}{σ} = \frac{30 - 100}{15} = -4.67$
$P(X \lt 30) = P(z \lt -4.67) = 1 - P(z \lt 4.67) = 1 - 0.9999 = 0.0001$
Hence, $P(Z \lt 30)$ should be considered as $\lt 0.0001$
