# Likelihood of a Single Event Worksheets

Determining the likelihood that something will happen is used in many different walks of daily life. This ranges from predicting the weather for tomorrow, to which basketball team will win the playoffs, to what are the chances that a coin will lead on tails. Probability is often described as to a level certainty. If we are looking at one time, we term this a single event. The range of certainty can be given a percentage value, like your weather app may tell you the chance of rain. More times than not you will find this range to more descriptive in the form of impossible, unlikely, equal, likely, or certain. We often perform experiments to test these measures. These statistics worksheets and lessons will teach students how to predict the outcome of single event probability problems.

### Aligned Standard: Grade 7 Statistics - 7.SP.C.5

- Chance of Chocolate Step-by-step Lesson- Find the probability of getting light chocolate.
- Guided Lesson - I know it says that it is a container full of marbles, but it does look a bit nuclear. Blame my nephew, he added the clip art to this one.
- Guided Lesson Explanation - Number three seems like common sense, but you will notice over all the sheets I come back to it often. It is a frequent test question.
- Practice Worksheet - Lots of different situations for you to work through. My favorite is the "official" party. What is that anyway?
- Matching Worksheet - Match each event to its probability.

- Answer Keys - These are for all the unlocked materials above.

### Homework Sheets

We run the probability in all formats for these.

- Homework 1 - Elena is playing Candyland with Ludo. If she rolls a 6- sided dice, what is the probability she will row a 4?
- Homework 2 - A bowl contains 4 blue, 6 brown, and 8 red stones. Without looking, if Jimmy picks a stone from the container, what is the probability that Jimmy will select a blue, brown, and red stone?
- Homework 3 - Sara has 10 packs of chips. 3 packs of the chips are banana. What is the probability that randomly selected banana chips?

### Practice Worksheets

The word problems here just got a bit, more wordy; if that's a thing...

- Practice 1 - Troy organizes a small party. There are 30 glasses of drinks at the party, 20 of which contain an orange flavored drink. What is the probability that a randomly selected drink will be orange flavored?
- Practice 2 - Lee has a fruit basket. The basket contains 15 apples and 20 oranges. Without looking, if Lee chooses from the basket, what is probability of selecting an apple or orange?
- Practice 3 - Teddy and Lucy are playing Around the World. If Teddy rolls a 6-sided dice, what is the probability he will row a 2?

### Math Skill Quizzes

We calculate the chance of events in a number of different ways.

- Quiz 1 - At the ice cream parlor, 7 out of 14 orders are sundaes. What is the probability that the next order will be for a sundae?
- Quiz 2 - Michale has 10 business cards. 5 of the cards are from CNG. What is the probability that a randomly selected card will be from CNG?
- Quiz 3 - Pony has 12 packs of face wash. 5 packs of the face wash are of oil free. What is the probability that randomly selected pack is oil free face wash?

### How to Determine the Probability of a Single Event?

Probability is a mathematical concept, which is the measurement of how likely it is for an event to occur. It is calculated as a ratio of favorable outcomes and the total number of possible outcomes. The probability always lies in the range starting from 0 to 1. Where 0 indicates that it will never occur and 1 indicates that it will definitely happen.

The formula to calculate the probability is; P(E) = (number of favorable outcomes)/(total number of possible outcomes).

Determining the probability of a single event is simple, but before we get into the details, you must understand what an event means. When we experiment, the total outcomes of this experiment are contained in a set that is labeled as sample space. An event is a subset of sample space. A sample space contains all possible cases, while an event only focuses on outcomes of interest only.

Now, consider that you experiment with "n" as the total number of outcomes of the event and the total elements in the sample space. If the possibility of each of the outcomes occurring is equal, the probability of each outcome is;

P = 1/n If the event we are interested in has an "r" number of outcomes, the probability of the event can be written as;

P = r/n If the event we are interested in includes all possible outcomes, the probability of each of these events can be written as;

P = n/n=1 To find the probability of a single event, you have to find out the exact number of possible outcomes and simply divide it by the total number of outcomes.