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Saturday, 31 October

JEE Main 2021 · MathsNumerical answerNumerical valueHardMulti-step

JEE Main 3 August 2021, Shift 1, Maths Q85

Question 85 of 90 in this shift, Maths question 25 of 30, Section B.

Let n≥1n \geq 1 be an odd integer and Sn=n3−(n−1)3+(n−2)3−…+(−1)n−113S_n = n^3 - (n-1)^3 + (n-2)^3 - \ldots + (-1)^{n-1} 1^3. If S199−4S99=106λS_{199} - 4 S_{99} = 10^6 \lambda, then the value of λ\lambda is ________.

Official answer

2

NTA final key.

Chapter
Sequences and Series
Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.