Online Test — Sequences and Series
10 Questions • 20 min • Chapter MCQ
20:00
Question 1 of 10
easy
The 10th term of the arithmetic progression 2, 7, 12, ... is:
47
52
42
37
Explanation: Here, first term a = 2 and common difference d = 7 − 2 = 5. The nth term is tⁿ = a + (n − 1)d. Thus, t10 = 2 + (10 − 1)5 = 2 + 45 = 47.
Question 2 of 10
medium
If x + 2, 3x, and 4x + 1 are in AP, then the value of x is:
1
2
3
4
Explanation: For terms to be in AP, 2b = a + c. So, 2(3x) = (x + 2) + (4x + 1) → 6x = 5x + 3 → x = 3.
Question 3 of 10
easy
The 20th term of the AP 1, 4, 7, ... is:
55
58
61
64
Explanation: T₂₀ = 1 + 19×3 = 58.
Question 4 of 10
medium
The sum of the infinite GP 8 + 4 + 2 + 1 + ... is:
12
14
16
18
Explanation: S∞ = 8/(1 − 1/2) = 16.
Question 5 of 10
easy
In the AP 3, 7, 11, 15, ..., the 10th term is:
35
39
43
47
Explanation: a = 3, d = 4. T₁₀ = 3 + 9×4 = 39.
Question 6 of 10
easy
The common difference of the AP 12, 8, 4, 0, ... is:
4
-4
8
-8
Explanation: d = 8 − 12 = -4.
Question 7 of 10
easy
Rahul invests ₹ 2000 in a scheme that gives 5% compound interest annually. The amount after 2 years will be:
₹ 2200
₹ 2205
₹ 2100
₹ 2305
Explanation: Compound interest forms a GP. A = P(1+r)ⁿ = 2000(1.05)² = 2000 × 1.1025 = 2205.
Question 8 of 10
easy
Which term of the AP 3, 8, 13, ... is 78?
15th
16th
17th
18th
Explanation: Let the nth term be 78. a = 3, d = 5. 78 = 3 + (n − 1)5 → 75 = 5(n − 1) → n − 1 = 15 → n = 16.
Question 9 of 10
easy
The geometric mean between 9 and 16 is:
10
11
12
13
Explanation: GM = √(9×16) = 12.
Question 10 of 10
easy
Identify the next term in the sequence: 2, 5, 10, 17, 26, ...
35
36
37
38
Explanation: The terms follow the pattern n² + 1. 1²+1=2, 2²+1=5, ..., 6²+1 = 37.