Answer
a) $\frac{5}{8}$
b) 1
c) $\frac{6}{8} = \frac{3}{4}$
Work Step by Step
a) Drawing a neither yellow nor white ball is equivalent to drawing a white ball, which has a probability of $\frac{5}{8}$ because there are 5 red balls and 8 total.
b) All the balls are either yellow, white, or red, so the probability is 1.
c) There are 6 balls that are not white, so there is a probability of $\frac{6}{8}$, which is equal to $\frac{3}{4}$.