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प्रश्न
Find n if `""^"n""C"_8 = ""^"n""C"_12`
उत्तर
`""^"n""C"_8 = ""^"n""C"_12`
If nCx = nCy, then either x = y or x = n − y
∴ 8 = 12 or 8 = n − 12
But 8 = 12 is not possible
∴ 8 = n – 12
∴ 8 + 12 = n
∴ 20 = n
∴ n = 20
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