Makoto and his friends rolled two fair number cubes 500 times and recorded the sum of the numbers shown on the cubes each time. On 42 of the trials the sum was 10. What will be the probability that the sum of the numbers shown on the cubes is 10 when two fair number cubes are rolled.
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To find the probability that the sum of the numbers shown on two fair number cubes is 10, we need to know how many possible outcomes there are and how many of those outcomes result in a sum of 10.
In this case, we know that Makoto and his friends rolled the number cubes 500 times and recorded the sum. We also know that on 42 of those trials, the sum was 10.
To find the probability, we can use the formula:
probability = (number of successful outcomes) / (total number of possible outcomes)
In this case, the number of successful outcomes is 42 (the number of trials where the sum was 10), and the total number of possible outcomes is 500 (the total number of trials). So the probability is:
probability = 42 / 500
Simplifying, we find:
probability = 0.084
Therefore, the probability that the sum of the numbers shown on the cubes is 10 when two fair number cubes are rolled is 0.084, or 8.4%.