Answer
See below.
Work Step by Step
The probability against $E$: $\frac{P(\text{not E})}{P(\text{not E})+P(E)}=1-P(E)$.
E.g. if we have $10$ balls, $3$ reds and $7$ blues, then the probability of not drawing a red ball when drawing one ball is: $1-P(red)=1-\frac{3}{10}=\frac{7}{10}$
