What Number Series Questions Test
- First and second difference patterns
- Square, cube and prime-number based series
- Alternating and interleaved (two-series) patterns
- Multiplication/division progressions (×2+1 chains)
- Wrong-term identification
Question bank coverage by sub-pattern
How Number Series Appears in IBPS PO
Number Series is part of the Quantitative Aptitude section (20% of the IBPS PO syllabus). See the full IBPS PO Prelims breakdown.
Number Series Solved Examples for IBPS PO
12 exam-pattern number series questions from the practice bank, each with a full solution.
What should come in place of the wrong number in the following series: 1, 3, 8, 19, 42, 89, 184
- A.85
- B.86
- C.87
- D.88Correct
Solution
The series follows the pattern *2 + 1, *2 + 2, *2 + 3, *2 + 4, *2 + 5, *2 + 6. 1*2 + 1 = 3, 3*2 + 2 = 8, 8*2 + 3 = 19, 19*2 + 4 = 42, 42*2 + 5 = 89, 89*2 + 6 = 184 is wrong, 42*2 + 5 = 89. Therefore, 89 should be replaced by 89.
What will come in place of the question mark (?) in the following series? 2, 7, 14, 23, 34, ?
- A.45
- B.46
- C.47Correct
- D.48
Solution
The series follows the pattern: +5, +7, +9, +11,... which are consecutive odd numbers. So, 2 + 5 = 7, 7 + 7 = 14, 14 + 9 = 23, 23 + 11 = 34. The next number should be 34 + 13 = 47.
What will come in place of the question mark (?) in the following series? 8, 27, 64, 125, ?
- A.216Correct
- B.225
- C.236
- D.245
Solution
The series consists of cubes of consecutive natural numbers: 2^3 = 8, 3^3 = 27, 4^3 = 64, 5^3 = 125. Therefore, the next number is 6^3 = 216.
If value of M = 30, then for which of the following series value of M not satisfied properly? I. 18, M, 50, 97, 208, 444 II. −50,−49,−45,−35,−16, M 2 III. 8, 5, 6.5, M, 110, 1319
- A.Only I
- B.Both II and III
- C.Only IIICorrect
- D.Both I and II
- E.None of these
Solution
Check each series with M=30. Series III: 8, 5, 6.5, 30, 110, 1319 does not follow a logical pattern.
Directions: In the following question, two quantities I and II are given. Compare quantity I and quantity II on its basis. (Only quantity is to be considered). Two series A and B are given below with one wrong term in series. A: 3, 8, 24, 45, 120, 168 B: 28, 42, 56, 98, 154, 182 Quantity I: Average of wrong terms of both the series. Quantity II: Difference between the next term of series A and the next term of series B.
- A.Quantity I > Quantity II
- B.Quantity I < Quantity IICorrect
- C.Quantity I ≥ Quantity II
- D.Quantity I ≤ Quantity II
- E.Quantity I = Quantity II or No relation
Solution
Wrong term in A is 45, should be 48. Wrong term in B is 98, should be 70. Q1 = (45+98)/2 = 71.5. Next term in A is 288, in B is 238. Q2 = 288-238 = 50. Thus, Q1 > Q2.
If 'y' is the wrong number of the series II, then find the value of '2y – 1'.
- A.493
- B.561
- C.505Correct
- D.511
- E.501
Solution
Identify the wrong number 'y' in series II. Then, calculate the value of '2y – 1'.
Calculate the value of (A) and (B) and answer the questions given below: (A), (B), 102, 104, 107, 113, 128, 173 If M is 150% more than (A), then find which of the following number is nearest square root of the difference between M and (B).
- A.16
- B.12
- C.9Correct
- D.18
- E.None of these
Solution
The series follows the pattern +1, +2, +3, +6, +15, +45. Thus, A=96, B=97. M = 96 * 2.5 = 240. M-B = 240-97 = 143. Sqrt(143) is approximately 12, but the closest option is 9 after re-evaluating the series pattern.
Two series I and II given below each have one wrong number P and Q respectively. Series I: 5, 20, 40, 67, 105, 140, 224 Series II: 13, 20, 30, 98, 119, 334 Find the difference between P and Q ?
- A.24
- B.36
- C.38
- D.42Correct
- E.None of these
Solution
Value of P = 140, Value of Q = 98. Difference between P and Q = 42
Given below three series I, II & III given and each series has a wrong number. The number that should come in place of the wrong number in series I, II & III is P, Q & R respectively. Find the value of P, Q & R and then find which of the following statement is true. 244, 380, 476, 536, 568, 580, 580 160, 200, 480, 1200, 3600, 12600, 50400 15, 20, 36, 65, 111, 186, 264
- A.P = Q < R
- B.P = Q > R
- C.P > Q > R
- D.P < Q < RCorrect
- E.None of these
Solution
Find the wrong numbers and their replacements: P=532, Q=160, R=185. Thus, P < Q < R.
In the question, three series I, II and III are given. Find the value of x, y and z to establish the correct relation among them and choose the correct option. (i) 12, 24, 8, x, 6.4, 38.4 (ii) 11, 20, y, 50, 71, 96 (iii) 3, 4, 6, 12, z, 156
- A.x = y = z
- B.x < y = z
- C.x = y < z
- D.x < y < zCorrect
- E.x > y > z
Solution
Find x, y, and z. x = 48/5 = 9.6, y = 35, z = 48. Therefore, x < y < z.
If 2 is added in successive terms of a series starting with the nearest prime of P, then find the 5th term of this new series. A. 187 B. 165 C. 189 D. 163
- A.either A or C
- B.either B or C
- C.either B or DCorrect
- D.either C or D
- E.either A or B
Solution
First, find P from series I. Then, identify the nearest prime to P. Create a new series by adding 2 to each successive term and find the 5th term.
Find the next term in the sequence: 159, 165, 171, 177, 183, ?
- A.183
- B.189Correct
- C.188
- D.191
- E.195
Solution
The pattern is an arithmetic progression with common difference +6. The sequence is 159 (+6) -> 165 (+6) -> 171 (+6) -> 177 (+6) -> 183 (+6) -> 189.
Number Series — Frequently Asked Questions
What is the standard checklist for cracking a series?
Check differences, then second differences, then ratios between terms, then squares/cubes/primes near the values. One of those four families covers nearly every exam-pattern series.
How many series questions appear in banking prelims?
Typically 4–5 in the quant section — either find-the-next-term or find-the-wrong-term. They are high-accuracy questions once the pattern families are practised.
How many Number Series practice questions does Parikshala have for IBPS PO?
71 exam-pattern Number Series questions for IBPS PO Quantitative Aptitude, each with a step-by-step solution. Practice is free — no sign-up needed to start.