Final answer:
The probability that a randomly chosen box of cereal is mini-sized and contains two prizes is calculated using a formula involving the individual probabilities and their union, yielding a probability of 0.2.
Step-by-step explanation:
The question asks for the probability that a randomly chosen box of cereal is a mini size and contains two prizes. To find this, we can use the formula P(A and B) = P(A) + P(B) - P(A or B), where P(A) is the probability of event A, P(B) is the probability of event B, and P(A or B) is the probability of either event A or event B occurring.
Given that P(mini size) = 0.6, P(two prizes) = 0.3, and P(mini size or two prizes) = 0.7, we can substitute these into our formula:
P(mini size and two prizes) = P(mini size) + P(two prizes) - P(mini size or two prizes)
P(mini size and two prizes) = 0.6 + 0.3 - 0.7
P(mini size and two prizes) = 0.2
Therefore, the correct answer is B) 0.2.