Complementary Events

Complementary Events

Secondary 2

The complementary of any event \(A\) is the event when \(A\) does not occur or happen.

Event \(A\) Complement of \(A\), \(A'\)
Win a game of chess

Don’t win a game of chess.

(Note: Don’t win is not the same as losing a game as the game can end with a draw.)

Taking the busNot taking the bus
Rainy dayNot a rainy day
Rolling a “6” on a dieNot rolling a “6” on a die

The complement of \(A\) is denoted by \(A'\) or \({{A}^{c}}\), consists of all the outcomes in which the event \(A\) does not occur.

\(\mathrm{P}\left( A' \right)=1-\mathrm{P}\left( A \right)\)

In other words, \(\mathrm{P}\left( \mathrm{not }A \right)=1-\mathrm{P}\left( A \right)\).

A card is drawn at random from the 26 playing cards shown above.

Find the probability of

  1. drawing a queen,
  2. not drawing a queen,
  3. an odd number,
  4. not an odd number.

For the number questions, count each ace as 1; kings, queens and jacks have no numerical value.

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs tuition enrolment.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.

Create a free account to practise similar questions.

Answer:(i) \(\frac1{13}\) (ii) \(\frac{12}{13}\) (iii) \(\frac5{13}\) (iv) \(\frac8{13}\)

Need help? Join our IP Math tuition programme.

Learn more