申論題

1. (10 points in total, 5 for each) (Two cold tablets (C) are unintentionally placed in a box containing two
aspirin tablets ( A ). The four are identical in appearance. One tablet is selected at random from the box and
is swallowed by the first patient. A tablet is then selected at random from the three remaining tablets and is
swallowed by the second patient. Define the following events as specific collections of simple events:

(b). Find the probability that an event A that neither patient obtained a cold tablet.