Probability problem long one
hey, guys, i have a really hard time with this, please help me
Suppose that the probability that an individual has been exposed to high levels of carbon monoxide in their lifetime is 0.06 and that the probability that they have been exposed to high levels of nitrogen dioxide is 0.03. What is the probability that an individual has been exposed to either high levels of carbon monoxide or high levels of nitrogen dioxide but not both?
All i know is that i have to add them because they asked for "or" then i have to subtract because it is a "not both" problem but i have no idea what to subtract
Thank you for your help guys