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Per NCERT, the second part of Aryabhata's verse describes Sₙ as which equivalent expression?
AFirst term × last term
BAverage of first and last terms × number of terms = (1 + n)/2 × n
CSum of first and last term divided by 2
DNumber of terms squared
Answer & Solution
Correct answer: B. Average of first and last terms × number of terms = (1 + n)/2 × n
Per NCERT §8.5, Aryabhata's second description: Sₙ = average × n = (1+n)/2 × n. Same as n(n+1)/2.
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