We want to know the probability of multiple possible outcomes that are not mutually exclusive. To do this, we use the addition rule with one step that we would not use if the possible outcomes were mutually exclusive.  Add the probabilities of each possible outcome, subtract from that sum the number counted twice, then reduce the answer to the least common denominator.

We want to know the probability of multiple possible outcomes that are not mutually exclusive. To do this, we use the addition rule with one step that we would not use if the possible outcomes were mutually exclusive. 

Add the probabilities of each possible outcome, subtract from that sum the number counted twice, then reduce the answer to the least common denominator. In our case, we are told that 2 of those who have a business degree are also entrepreneurs therefore we need to subtract to from the total to get the correct probability.

Bear in mind how the addition rule applies here. This will be a lengthy application, but applied properly, it will see you through this problem. It helps to think of this as four events that are not mutually exclusive - drawing a queen, drawing a jack, drawing a king or drawing a diamond. We then realize that we have to avoid counting the king, queen and jack of diamonds twice.

In this case, we want to know the probability of multiple, mutually exclusive possible outcomes. The possible outcomes are mutually exclusive because one can of food could not be both beans and tomato sauce. To determine the probability of the two possible outcomes, add them together and then find the least common denominator.

In the single roll of a dice, rolling a 2 is mutually exclusive of rolling a 4. When a question asks for the probability of event A "or" event B, the probability is the sum of each event.

First, find the probability of each individual event.

Because the problem asks for a 2 OR a 4, add the indivual probabilities together.

In the draw of a marble, picking a red is mutually exclusive of picking a green marble. When a question asks for the probability of event A "or" event B, the probability is the sum of each event.

First, find the probability of each event occuring.

Because the problem asks for the probability of either red OR green, we add the two probabilities.

In a single draw of a card, drawing a heart is mutually exclusive of drawing a spade, so we can use the addition rule to find the probability of a heart of a spade.

First, you must find the probability of each seperate event.

To find the probability of a heart or a spade, just add the probability of each event occuring.

This problem asks for the probability of one event or another, so we will be using the addition rule. Because the event drawing a heart is not mutually exclusive from the event drawing a Jack, we must subtract the probability of getting both. Otherwise, we will double-count the Jack of Hearts.

First, find the probability of each event occuring

Now, find the probability of drawing both a Jack and a Heart. There is one card that is both.

Now, solve the equation.

You must use the addition rule of probability which is the probability of either of two dependent events happening is the sum of the probabilities of each dependent event minus the probabilty of both happening (this eliminates double counting possible out comes).  The probabilty of getting an ace is  and the probability of getting a spade is .  The probability of getting an ace of spades is .  The final answer would then be = . 

Billy plays baseball 40%+football 30% gets 70%.

But he plays both 15% so:  

%