Answer:
0.2333 = 23.33% probability that both of them have the secret decoder ring
Step-by-step explanation:
The cereals are chosen without replacement, which means that the hypergeometric distribution is used to solve this question.
Hypergeometric distribution:
The probability of x successes is given by the following formula:
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
45 boxes, which means that
22 have the secret decoder ring, which means that
Two boxes, which means that
What is the probability that both of them have the secret decoder ring?
This is P(X = 2). So
0.2333 = 23.33% probability that both of them have the secret decoder ring
