This seems like it should be easy but I can't get my mind around it:

"Of all the cars sold at a car dealership, 80% are not convertibles, 40% are red, and 5% are red convertibles. Given that a car sold by a salesperson at this dealership is a convertible, what is the probability that it is red?"

Any help would be appreciated, even if it's just a starting point.

Thanks!