Final answer:
Without the given value of p, the probability of success, we cannot provide the exact decimal value for q, the probability of failure. If p were known, q would be equal to 1 - p.
Step-by-step explanation:
The student's question pertains to the concept of probability, where q is the probability of failure on a single trial.
Given that p + q = 1 and knowing the probability of success (p), we can find the value of q as the complement of p. Since the probability of success on exactly two patients would be represented by p, and no specific value for p is provided, we cannot calculate the exact decimal value of q.
However, if p were known, calculating q would involve subtracting p from 1, with the solution expressed to the appropriate number of significant figures and proper units.