Formula of nᵗʰ term of an A.P is:
- a+nd
- a+(n−1)d
- a+(n+1)d
- a(n−1)d
Show answer and explanation
Answer: B. a+(n−1)d
Standard AP formula: aₙ=a+(n−1)d.
Practise 28 real Federal Board questions on Sequences and Series from 2023 to 2026. See the answer and explanation as soon as you answer.
Sequences and Series is one of the 14 main chapters in our Federal Board FSC Mathematics question bank (11th class), and about 6% of its real questions come from it. Tayyari Karo has 28 real questions on this chapter from 2023 to 2026; 13 are multiple choice and marked instantly, and the rest are short and long questions with a model answer. By difficulty: 12 easy, 11 medium, 5 hard.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
These are real past-paper questions. Think of your answer first, then open the explanation.
Formula of nᵗʰ term of an A.P is:
Answer: B. a+(n−1)d
Standard AP formula: aₙ=a+(n−1)d.
In an arithmetic sequence, a₁=5 and a₁₅=75. What is the common difference?
Answer: C. 5
d=(a₁₅−a₁)/14=(75−5)/14=5.
What is the first term of an infinite geometric series whose sum is 10, and common ratio 0.6?
Answer: A. 4
a=S∞(1−r)=10×0.4=4.
In an arithmetic sequence, if a₁=3 and d=2, then 5th term is:
Answer: B. 11
a₅=a₁+4d=3+8=11.
The last digit of 7¹⁰ is:
Answer: D. 9
Units digit of 7ⁿ cycles 7,9,3,1 (period4); 10 mod4=2 ⇒ digit 9.
The nth term of a series 3×1² + 5×2² + 7×3² + ... is:
Answer: D. (2n+1)n²
Each term is (2n+1)·n²: check n=1: 3×1=3 ✓; n=2: 5×4=20 ✓; n=3: 7×9=63 ✓.
Find the sum of the geometric series 2/3, −1, 3/2, … up to 5 terms.
a=2/3, r=−1÷(2/3)=−3/2
S₅ = a(1−r⁵)/(1−r) = (2/3)(1−(−3/2)⁵)/(1−(−3/2)) = (2/3)(1+243/32)/(5/2)
= (2/3)(275/32)(2/5) = 55/24
A bouncing ball rebounds 80% of its previous height. If the ball is dropped from a height of 50 meters, find the total distance traveled by the ball before coming to rest.
Total distance = h + 2hr/(1−r), h=50, r=0.8
= 50 + 2(50)(0.8)/0.2 = 50+400
= 450 meters
| Session | Questions |
|---|---|
| 2026 Annual | 7 |
| 2025 1st Annual | 8 |
| 2025 2nd Annual | 7 |
| 2024 Annual | 3 |
| 2023 Annual | 3 |
28 real Federal Board (FBISE) Mathematics questions on Sequences and Series from 2023 to 2026, for 11th class. Each one shows the session it came from.
No. We could not find an official FBISE marking scheme for these papers, so the answers and explanations are written by Tayyari Karo for practice. Check anything important with your teacher or textbook.
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