please help

Seventy-five cars sit on a parking lot. Thirty have stereo systems, 30 have air conditioners and 40 have sun roofs. Thirty of the cars have at least two of these three options, and 15 have all three. How many cars on the lot have at least one of the three options How many have exactly one (Hint: Try the inclusion-exclusion formula, carefully.) (Input your answers as numbers with no spaces.)