Aly is looking for a new car. she has test-driven two cars but can only purchase one. the probability that she will purchase car a is 0.47 and the probability that she will purchase car b is 0.35. what is the probability that she will not purchase either car a or car b? 0.12 0.41 0.82 0.18

The probability of buying A or B is P(A∪B) = 0.47 + 0.35

P(A∪B) = 0.82
But the probability of NOT buying either is :
 P(A'∪B') = 1 - 0.82 = 0.18

P(A) = 0.47
P(B) = 0.35
The probability of an event occurring ranges from 0 to 1, or 0 to 100%.
P(not A or not B) would be the complement of the events occurring.
The probability of an event and its complement is always 1.
Ex.  P(A) + P(A') = 1
P(A) + P(B) = 0.47 + .35 = 0.82
P(not A or not B) = 1 - 0.82 = 0.18
Last option