Given that 3 or more packages contain a substantial number of broken cookies, what is the probability that exactly 4 packages contain a substantial number of broken cookies

The problem above is an example of conditional probability. From the name itself, it gives you a condition that a certain event has already happen, or is sure to happen. In this case, the probability would be 100% or 1. The condition says that the probability is 100% if the packages are more than 3. Since, 4 is considered to be more than 3, then the probability is 100%.