Probability: the measure of the likelihood that an event will occur.
There are two types of events in probability: simple events and compound events. Simple events... are simple. Simple events are the likelihood of only one event. A simple event would be like: What is the probability of rolling a 4 on a standardized die? That would be 1/6. If you don't get that, to calculate simple events, create a ratio of the number of times your number shows up (4 only appears once on the die)to the number of possible outcomes(in this case 6, there are 6 faces on a die). Anyway, to the history. Probability was invented by two French mathematicians, Blaise Pascal and Pierre de Fermat. Pascal should technically be credited more because he really came up with the idea. See, Pascal was prompted with the idea of probability by a popular dice game where you would throw a pair of dice 24 times. You needed to bet on whether or not the dice would both land on 6 at least once. Pascal then began to correspond(exchange letters) with Fermat. This eventually formulated the basis for theoretical probability. Later, more mathematicians wrote books and developed different styles of probability, so really, Pascal and Fermat's creation was a simple event. #badpun... Anyways, compound events are events with at least two events, like calculating the probability of a 5 on a die and red on a spinner. There are 3 types of compound events: mutually exclusive events, independent events, and dependent events. Mutually exclusive events are two events that cannot both occur. The formula for that is P(A or B)= P(A)+P(B). For example if I wanted to find the probability of landing on blue or red on a blue, red, yellow, and green spinner, I would solve it like this. P of blue=1/4. P of red= 1/4. 1/4 +1/4=1/2. Therefore, the probability of landing on a blue or red is 1/2. A type of mutually exclusive event is a complementary event. Complementary events are mutually exclusive events that probabilities together are always equal to 1. 1 in the probability world means that it is certain to happen. Independent events are two events that do not affect each other. The formula for that is P(A and B)= P(A) x P(B). Basically, when calculating the probability of a die and spinner, you are calculating independent events. Like the probability of 2 and green. Dependent events are two events that has one event depending on the other. The formula for that is P(A and B)= P(A) x P(B)given A. For example, what is the probability of picking two pink marbles in a row if there are 7 pink and 3 orange marbles in a bowl. Remember, the odds of getting a pink change when you have already picked one out. Answer the marble probability question in the comments below. See Ya!
