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Question
Evaluate `("n"!)/("r"!("n" - "r")!)` for n = 15, r = 10
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Solution
n = 15, r = 10
∴ `("n"!)/("r"!("n" - "r")!) = (15!)/(10!(15 - 10)!)`
= `(15!)/(10! xx 5!)`
= `(15 xx 14 xx 13 xx 12 xx 11 xx 10!)/(10! xx 5 xx 4 xx 3 xx 2 xx 1)`
= 3003
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