Test your knowledge with free interactive questions on Seneca — used by over 10 million students.

Probability

The probability of an event is the likelihood of it happening. Probabilities are between 0 and 1 and the higher the probability, the more likely the event is to occur. Probabilities can be given as decimals, fractions or percentages.

Notation

Notation

  • For a fair dice, P(6) means the probability of rolling a 6.
  • For a bag of coloured balls, P(red) means the probability of a red ball being pulled out.
Relative frequency

Relative frequency

  • The relative frequency of an outcome during a probability experiment is an estimate of the probability of that outcome.
  • The more trials performed during the experiment, the more accurate the estimate.

Sum of Probabilities

If all the possible outcomes of an event are listed then the sum of the probabilities of those events will be 1.

Probabilities add up to 1

Probabilities add up to 1

  • For any event:
    • P(event happens) + P(event doesn’t happen) = 1.
Rules

Rules

  • The probabilities of a set of outcomes add up to 1 if:
    • All possible outcomes are included
    • Only one outcome can happen at a time.
Jump to other topics
1

Numbers

2

Equations, Formulae & Identities

3

Sequences, Functions & Graphs

4

Geometry

5

Vectors & Transformation Geometry

6

Statistics & Probability

Practice questions on Probability

Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
Answer all questions on Probability

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium