Final answer:
Events can be independent or dependent based on whether the outcome of one event affects the probability of another event occurring. When events are sampled without replacement, they are considered dependent because the probabilities for the second pick are affected by the result of the first pick.
Step-by-step explanation:
Two events A and B are independent events if the knowledge that one occurred does not affect the chance the other occurs. Sampling may be done with replacement or without replacement. With replacement, events are considered to be independent. Without replacement, events are considered to be dependent. In sampling without replacement, the probabilities for the second pick are affected by the result of the first pick.