What are independent and dependent events? How about replacement/without replacement?

Answer 1

If
T = the total number of items in a set
A = the total number of items in a subset
B = the total number of items in another subset
Independent events' probabilities are not affected by any other events (if you want to take the probability of two events happening, you would just be multiplying the individual probability of each happening). An example is replacement. If I want the probability of the same event happening with replacement, I take the probability of taking an item out of a set, put it back, and then take the probability again.
Example: p(A,A) = A/T * A/T
However, dependent events' probabilities are affected by other events (taking the probability of it by itself would not be the same as taking the independent events' probabilities). An example is without replacement. If I want the probability of the same event happening without replacement, I take the probability of taking an item out of a set, keep it out, and then take the probability again.
Example: p(A,A) = A/T * (A-1)/(T-1)
ur welcome :)