This topic builds on your previous understanding of probability to include more complicated examples and guides you through the working-out process.
Emma has 6 pink, 16 green and 8 blue buttons in a box. What is the probability that she will randomly select a blue button? Write your answer as a percentage.
First, calculate the total number of buttons:
Next, represent the number of blue buttons as a fraction of the total:
Finally, since the question asks for the answer in percentage form, convert the fraction to a percentage:
Emma removes 5 pink buttons from the box. What is the probability that she will now select a blue button? Write your answer as a decimal.
Calculate the new total number of buttons:
We must use this number as the new total.
Use this new total to find the fraction representing blue buttons:
Finally, convert this fraction to a decimal:
Jerry has a fair hexagonal spinner with 6 numbers in total. The probabilities for landing on specific numbers are:
Write the numbers on the spinner.
First, convert each fraction to have a denominator of 6, as there are 6 numbers on this spinner:
Use the numerators to find how many times each number appears on the spinner:
Complete the spinner.
Therefore, on the spinner, the numbers should be distributed based on these probabilities to make it a “fair” spinner. The sum of these probabilities is , confirming it as a fair spinner. Note that the placement of the numbers doesn’t matter.