Employment data at a large company reveal that 72% of the workers are married, that 44% are

Question:

Employment data at a large company reveal that 72% of the workers are married, that 44% are college graduates, and that half of the college grads are married. What's the probability that a randomly chosen worker
a) Is neither married nor a college graduate?
b) Is married but not a college graduate?
c) Is married or a college graduate?