Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!

Home > Maths > Handling data > Probability

Maths

Probability

Print

Finding probabilities

When you throw a die (plural: dice), there are six possible different outcomes. It can show either 1, 2, 3, 4, 5 or 6.

But how many possible ways are there of obtaining an even number? There are three possibilities: 2, 4 and 6.

The probability of obtaining an even number is 3/6 (= 1/2 or 0.5 or 50%)

The probability of an outcome = number of ways the outcome can happen ÷ total number of possible outcomes

Question

Q1. How many outcomes are there for the following experiments? List all the possible outcomes.
a) Tossing a coin
b) Choosing a sweet from a bag containing 1 red, 1 blue, 1 white and 1 black sweet.
c) Choosing a day of the week at random.

Q2. Sindhu writes the letters of the word 'MATHEMATICS' on separate cards and places them in a bag. She then draws a card at random.

A person drawing letters on cards

What is the probability that Sindhu chooses the letter 'A'?

Answer

A1.
a) There are two possible outcomes (head and tail).
b) There are four possible outcomes (red, blue, white and black).
c) There are seven possible outcomes (Sunday, Monday, Tuesday, Wednesday, Thursday, Friday and Saturday).

A2. There are 11 letters in MATHEMATICS, 2 of which are A, so the probability that Sindhu chooses the letter A is 2/11.

Activity

Probability activity

What are the chances of you trying this activity?

Play

Gut Instinct

Can you match Viral Vinnie's appetite for English, Maths and Science?

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.