A check of dorm rooms on a large college campus revealed that 38% had refrigerators, 52% had

Question:

A check of dorm rooms on a large college campus revealed that 38% had refrigerators, 52% had TVs, and 21% had both a TV and a refrigerator. What's the probability that a randomly selected dorm room has
a) A TV but no refrigerator?
b) A TV or a refrigerator, but not both?
c) Neither a TV nor a refrigerator?