WEBVTT
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There are 50 pencils in a pot.
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17 are blue, 10 are red, and the rest are green.
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A pencil is taken from the pot at random.
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Calculate the probability that the pencil is green.
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We are told in the question that there are 50 pencils in total.
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17 of them are blue; 10 of them are red.
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We are told that the rest of the pencils are green.
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To calculate the number of green pencils, we need to add 10 and 17 and subtract it from 50.
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17 plus 10 is equal to 27.
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And 50 minus 27 is equal to 23.
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We could work this out by finding the difference between 27 and 50 on our number line.
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The difference between 27 and 30 is three.
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And the difference between 30 and 50 is 20.
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Three plus 20 is equal to 23.
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Therefore, the difference between 27 and 50 is 23.
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There are 23 green pencils in the pot.
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We are asked to calculate the probability that the pencil selected at random is green.
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Probability can be written as a fraction.
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The number of successful outcomes is the numerator.
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And the number of possible outcomes is the denominator.
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A successful outcome, in this case, is selecting a green pencil.
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Therefore, the numerator will be the number of green pencils.
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The number of possible outcomes is the total number of pencils in the pot.
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We have worked out that the number of green pencils was 23.
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Therefore, our numerator is 23.
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There were 50 pencils altogether.
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So our denominator is 50.
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The probability of selecting green pencil from the pot is 23 out of 50 or twenty three fiftieths.