21.1 Fundamental counting principle

Fundamental counting principle

The fundamental counting principle can be very helpful when you need to figure out the possible number of outcomes of multiple events. The principle essentially works like this: If there are m possible ways for an event to occur, and n possible ways for another event to occur, there are m x n possible ways for both events to occur. In this lesson, we will apply the principle to real-life scenarios to see how it works.


    • a)
      How many pieces of clothing are you bringing all together?
    • b)
      If an outfit consists of a shirt and a pair of pants, how many different sets of outfit can you make?
      Determine the answer by using:
      (i) a tree diagram
      (ii) the fundamental counting principle
  • 5.
    How many odd four digit numbers are there? An example of a four digit number is 3581, while 0492 is a three digit number.
  • 6.
    Use only the digits 2, 4, 5, 6, 7, 8 and 9 to produce four digit numbers.
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Fundamental counting principle

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