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What is the probability of rolling an odd number on a fair die?
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A fair die has six faces numbered one, two, three, four, five, and six.
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We were asked to work out the probability of rolling an odd number.
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A number is odd if it is not divisible exactly by two.
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In this case, the numbers one, three, and five are odd, whereas two, four, and six are even as they are divisible by two.
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The probability of an event occurring can be written as a fraction where the numerator is the number of successful outcomes, what we want to happen, and the denominator is the number of possible outcomes, everything that can happen.
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In this case, there are three odd numbers.
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Therefore, our numerator is three.
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The denominator is six as there are six numbers on the dice.
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There are six possible outcomes.
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The fraction three sixths can be simplified as the numerator and denominator are both divisible by three.
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Remember, whatever you do to the top, you must do the bottom.
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Dividing the numerator by three gives us one as three divided by three is equal to one.
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And dividing the denominator by three give us an answer two.
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Six divided by three equals two.
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This means that the probability of rolling an odd number on a fair dice is one-half.
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This could also be written as a decimal as 0.5 or a percentage as 50 percent.