A batch of pilles consists of 7 that are good and 3 that are defective( because they have of 7 that are good and 3 that are defective(because they have the wrong amount of drug). three pills are randomly chosen and tested.
a. How many different sample of pilles are possibly when three pills are randomly chosen (without replacement from the 10 that are available?
b. Determine the probability that all three of defective pills are selected,