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Per NCERT, the sum 25 + 26 + 27 + ... + 58 can be computed as which expression?
A25 + 58 = 83
BS₅₈ − S₂₄ = (58×59)/2 − (24×25)/2 = 1711 − 300 = 1411
CJust 58 − 25 = 33
D58 × 25 = 1450
Answer & Solution
Correct answer: B. S₅₈ − S₂₄ = (58×59)/2 − (24×25)/2 = 1711 − 300 = 1411
Per NCERT §8.5, partial sums use Sₙ − Sₘ₋₁. (58×59)/2 = 1711; (24×25)/2 = 300; difference = 1411.
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