There are three sections of a mathematics course available at convenient times for a student.

There are three sections of a mathematics course available at convenient times for a student. There is a 24% chance that Professor Jones gives a final exam, a 15% chance that Professor Cates gives a final exam, and a 10% chance that Professor Smithson gives a final exam. At other times there are two biology sections, and in those the probabilities of a final are 5% and 12%. Find the probability that a student who randomly chooses one mathematics course and one biology course has to take at least one final examination.