WEBVTT
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Which of the following is equal to 41 πΆ five?
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Is it (A) 41 π five divided by five factorial, (B) 41 π five divided by five, (C) 41 π five multiplied by five factorial, or (D) 41 π five multiplied by five?
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We begin by recalling our formulae for permutation and combination.
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The permutation πππ is equal to π factorial divided by π minus π factorial.
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And the combination ππΆπ is equal to π factorial divided by π minus π factorial multiplied by π factorial.
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Combining these two formulae, we see that ππΆπ is equal to πππ divided by π factorial.
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In this question, π is equal to 41 and π is equal to five.
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This means that 41 πΆ five is equal to 41 π five divided by five factorial.
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The correct answer is therefore option (A).