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Probability ProblemsIn this lesson we will learn how to solve simple probability problems with a number cube. Double-click the play button to watch the following video.
DefinitionThe probability of an event measures the likelihood that the event will occur.FormulaWhen trying to find the probability of an event, use this formula:P(event) = number of favorable outcomes / total number of outcomesWhen solving problems about a number cube (or a die), you should know that the total number of outcomes is 6, because a cube has six faces. Therefore, the denominator is six. To find the numerator, count the number of favorable outcomes. Let's try some examples.Example 1A die is rolled once. What is the probability of getting an odd number?SolutionThe following outcomes are favorable: getting number 1, getting number 3, or getting number 5.There are 3 favorable outcomes (the above outcomes). Therefore the numerator is 3. The denominator is 6 because there are 6 unique numbers on a die. P(odd number) = 3/6 = 1/2 = 0.50 = 50% Example 2A die is rolled once. What is the probability of getting a prime number less than four?Solution2 and 3 are the only prime numbers less than four. Since there are two favorable outcomes, the numerator is two.The denominator is 6 because there are 6 unique numbers on a die. P(prime number less than 4) = 2/6 = 1/3 = 0.333... = 33% Return from Probability Problems with a Number Cube to Probability Videos
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