Class 11 Mathematics — Chapter 9: Sequences and Series
66 practice questions · 22 Easy · 22 Medium · 22 Hard
Practise Class 11 Mathematics Chapter 9, "Sequences and Series", with 66 NCERT-aligned multiple-choice questions. The set is split into 22 Easy, 22 Medium and 22 Hard questions, so you can warm up on the fundamentals and then push into the exam-level problems that separate top scorers in CBSE Board exams, JEE Main and JEE Advanced.
"Sequences and Series" is one of the chapters where problem-solving speed, formula recall and step-by-step reasoning really pays off. Each MCQ on this chapter is timed and uses exam-grade marking (+2 correct, −1 wrong, 0 skipped), training the same accuracy-under-pressure that real papers demand. Every question carries a short explanation, so a wrong answer becomes a quick lesson rather than a dead end — the fastest way to close gaps before a test.
Use this chapter as targeted revision: attempt the Easy set first to confirm your basics on Sequences and Series, then move to Medium and Hard to test application and problem-solving. Your accuracy, streaks and XP save automatically, and the chapter feeds into your overall Class 11 Mathematics mastery score. A few sample questions are shown below; sign in free to practise all 66.
Key concepts: Sequences and Series (Class 11 Mathematics)
This chapter covers arithmetic and geometric progressions, their sums, the arithmetic and geometric means, and special series.
- Arithmetic progression (AP)
- Constant common difference d; nth term aₙ = a + (n−1)d.
- Geometric progression (GP)
- Constant common ratio r; nth term aₙ = a·r^(n−1).
- Sum of AP / GP
- AP: Sₙ = n/2[2a + (n−1)d]; GP: Sₙ = a(rⁿ − 1)/(r − 1), r ≠ 1.
- Means
- Arithmetic mean of a, b is (a+b)/2; geometric mean is √(ab); AM ≥ GM.
- Infinite GP
- If |r| < 1, the infinite GP sum converges to a/(1 − r).
Key formulas — Sequences and Series
💡 Exam tips for Sequences and Series
- Check whether the sequence is AP (constant difference) or GP (constant ratio) before choosing the formula.
- The infinite-GP sum a/(1−r) is valid only when |r| < 1.
Sample questions
nth term of AP a, a+d, a+2d, ... :
Standard AP formula.
Sum of n terms of AP:
Sₙ = n/2 [2a + (n−1)d].
Sum of infinite GP, |r|<1:
Converges to a/(1−r).
Sequences and Series — FAQs
What are the key concepts in Class 11 Mathematics Sequences and Series?+
This chapter covers arithmetic and geometric progressions, their sums, the arithmetic and geometric means, and special series. Key ideas include Arithmetic progression (AP), Geometric progression (GP), Sum of AP / GP, Means, Infinite GP.
What does Class 11 Mathematics Chapter 9 (Sequences and Series) cover on XamBaaz?+
It covers 66 NCERT-aligned MCQs on "Sequences and Series" — 22 Easy, 22 Medium and 22 Hard — each with a timed quiz and an instant explanation, suitable for CBSE Board exams, JEE Main and JEE Advanced.
Are these "Sequences and Series" questions free to practise?+
Yes — sign in with Google to practise "Sequences and Series" free. Full unlimited access is ₹999/year (limited-time launch price), with no per-chapter charges.
How should I revise "Sequences and Series" for the exam?+
Start with the Easy quiz to confirm your fundamentals, then attempt Medium and Hard for application-level practice. Review each explanation, retry the questions you miss, and track your accuracy on this chapter until it is consistently high.
Practise all 66 questions free
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