A traffic analyst supervisor wants to examine the worst day and time during a week to commute. He finds that 35% of accidents happen on a Friday and that 23% of the accidents occur at around 2 p.m. He also finds that 5% of accidents occur on Friday at around 2 p.m.

a. What is the probability that an accident that occurs on Friday does not occur around 2 p.m.?

b. Are the events “accident occurs on Friday” and “accident occurs around 2 p.m.” statistically independent?