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840=2 times 2 times 2 times 3 times 5 times 7
Formula:
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<span>Note: , where nPr is the formula for permutations of n objects taken r at a time.</span>
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Example:
<span>How many different committees of 4 students can be chosen from a group of 15?
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Answer:
<span>There are possible combinations of 4 students from a set of 15.</span>
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There are 1365 different committees.</span></span></span>
