Probability of Illness A or B

A doctor is assessing the probability of two separate illnesses, A and B, in a population. It is known that:

- The probability of an individual having illness A is $P(A) = 0.1$.

- The probability of an individual having illness B is $P(B) = 0.15$.

- The probability of an individual having both illnesses A and B is $P(A ext{ and } B) = 0.03$.

Determine the probability that an individual has either illness A or illness B but not both. This can be calculated using the formula:

$P(A ext{ or } B) = P(A) + P(B) - P(A ext{ and } B)$