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Question
If nC12 = nC8, then n is equal to ______.
Options
20
12
6
30
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Solution
If nC12 = nC8, then n is equal to 20.
Explanation:
Given that nC12 = nC8 ......[∵ nCr = nCn-r]
nC12 = nCn-8
∴ n – 8 = 12
⇒ n = 12 + 8
= 20
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