1. The problem is to find the probability of events 4 and 5 using the complementary events formula. 2. The complementary events formula states that $P(A) = 1 - P(A^c)$, where $A^c$ is the complement of event $A$. 3. To find $P(4)$, we calculate $P(4) = 1 - P(4^c)$. 4. Similarly, to find $P(5)$, we calculate $P(5) = 1 - P(5^c)$. 5. You need to know or calculate the probabilities of the complements $P(4^c)$ and $P(5^c)$ to proceed. 6. Once you have those, substitute into the formula and simplify to get the final probabilities. 7. This method is useful when the complement probabilities are easier to find than the direct probabilities.