Every year, thousands of aspirants chase the SBI PO dream, but only those who master speed and accuracy in Quantitative Aptitude truly stand out. Among the trickiest yet most rewarding topics is the Missing Number Series. It looks simple at first glance, but examiners design patterns that test your intuition, calculation speed, and ability to spot hidden logic. In this blog, we’ll uncover the Top 40 Missing Number Series types with examples, strategies, and practice insights that can transform your preparation.
Top 40 Missing Number Series for SBI PO 2026
Missing Number Series questions demand sharp observation and quick recognition of mathematical patterns. From cubes and squares to prime differences and alternating multiplications, these series cover a wide range of logic.
Below, we break down the Top 40 types with examples to help you solve them in under 30 seconds.
1. Cube Patterns
Cubes are one of the most common foundations of missing number series. Examiners love to test whether aspirants can quickly spot consecutive cube values hidden in a sequence. Recognizing these instantly saves precious seconds in the exam.
Example: 8, 27, 64, ?
Logic: Consecutive cubes ($2^3$, $3^3$, $4^3$).
Answer: 125 ($5^3$).
2. Prime Multiples
Prime numbers often sneak into series as multipliers. When combined with a base like 6 or 8, they create tricky progressions. Spotting prime multiples early ensures you don’t waste time chasing random differences.
Example: 18, 30, 42, 66, ?
Logic: Multiples of 6 with prime factors (6×3, 6×5, 6×7…).
Answer: 78.
3. Difference Increments
Incremental differences are a favorite examiner trick. They start small and grow steadily, forcing you to notice the pattern of addition. Missing this can derail your speed, so train your eyes to catch it fast.
Example: 5, 8, 14, 23, ?
Logic: Differences of +3, +6, +9.
Answer: 35.
4. Perfect Squares Addition
Perfect squares often appear as hidden add‑ons in series. If you can connect terms to square values, the sequence becomes clear. This pattern rewards those who revise squares thoroughly before the exam.
Example: 4, 68, 168, ?
Logic: Adding consecutive squares ($2^2$, $8^2$, $10^2$).
Answer: 34.
5. Prime Number Differences
Sometimes the difference between terms follows prime numbers. This subtle twist makes the series harder to crack unless you’re comfortable with prime progressions. Quick recognition here can give you a scoring edge.
Example: 124, 131, 142, 155, ?
Logic: Adding prime gaps (7, 11, 13…).
Answer: 172.
6. Multiples of 16
Multiplication tables are a hidden weapon in missing series. Examiners often disguise them with larger bases like 16, expecting aspirants to overlook the obvious. Spotting them quickly is a huge time saver.
Example: 16, 32, 48, ?
Logic: Multiplication table of 16.
Answer: 64.
7. Unit Digit Analysis
Unit digits can confirm or break your guess. Many series rely on multiplication where the unit digit reveals the next term. Training in this technique builds confidence and accuracy under pressure.
Example: 12, 36, 108, ?
Logic: Multiplication with unit digit checks.
Answer: 324.
8. Decreasing & Increasing Series
Series often mix decreasing and increasing multipliers to confuse aspirants. Recognizing the shift in direction is key. Once spotted, the logic flows smoothly, and the answer falls into place.
Example: 128, 640, 1280, ?
Logic: Multiply by 5, then double, then multiply by 4.
Answer: 3584.
9. Alternate Multiplication & Division
Alternating operations are a clever twist. Multiplication followed by division creates a rhythm that only sharp observation can catch. Missing this rhythm leads to wasted time and wrong answers.
Example: 9, 45, 7.5, 37.5, ?
Logic: ×5, ÷6 alternately.
Answer: 45.
10. Multiplication Table Patterns
Simple multiplication tables often hide in plain sight. Examiners expect aspirants to overlook them under exam stress. Recognizing these instantly can give you quick marks with minimal effort.
Example: 40, 48, 56, ?
Logic: Multiples of 8 (8×5, 8×6…).
Answer: 64.
11. Consecutive Addition
Adding consecutive integers is a straightforward but effective trick. It tests whether aspirants can extend a simple addition sequence without overthinking. Quick spotting here ensures easy scoring.
Example: 70, 73, 77, ?
Logic: Add 3, 4, 5…
Answer: 82.
12. Products of Consecutive Numbers
Products of consecutive numbers create elegant series. They look complex but follow a clear multiplication logic. Recognizing this saves time and builds confidence in tackling tougher series.
Example: 12, 20, 30, 42, ?
Logic: 3×4, 4×5, 5×6, 6×7…
Answer: 56.
13. Double & Add Pattern
Example: 3, 7, 15, 31, ?
Logic: Double the previous term and add 1.
Answer: 63.
14. Factorial Connection
Example: 1, 2, 6, 24, ?
Logic: Factorials (1!, 2!, 3!, 4!).
Answer: 120 (5!).
15. Fibonacci Twist
Example: 2, 3, 5, 8, 13, ?
Logic: Fibonacci sequence.
Answer: 21.
16. Square Minus Series
Example: 0, 3, 8, 15, ?
Logic: (n^2 – 1).
Answer: 24.
17. Odd Number Multiples
Example: 3, 9, 27, ?
Logic: Multiply by 3 each time.
Answer: 81.
18. Even Number Addition
Example: 2, 6, 12, 20, ?
Logic: Add consecutive even numbers.
Answer: 30.
19. Prime Squares
Example: 4, 9, 25, 49, ?
Logic: Squares of primes (2², 3², 5², 7²…).
Answer: 121 (11²).
20. Halving Pattern
Example: 256, 128, 64, ?
Logic: Divide by 2 each step.
Answer: 32.
21. Alternate Addition & Subtraction
Example: 10, 15, 12, 17, ?
Logic: +5, −3 alternately.
Answer: 14.
22. Reverse Fibonacci
Example: 21, 13, 8, 5, ?
Logic: Fibonacci backwards.
Answer: 3.
23. Multiplication by Increasing Integers
Example: 2, 4, 12, 48, ?
Logic: Multiply by 2, 3, 4…
Answer: 240.
24. Square Roots
Example: 1, 4, 9, 16, ?
Logic: Perfect squares.
Answer: 25.
25. Triangular Numbers
Example: 1, 3, 6, 10, ?
Logic: Sum of consecutive integers.
Answer: 15.
26. Cube Minus One
Example: 7, 26, 63, ?
Logic: (n^3 – 1).
Answer: 124.
27. Multiples of 11
Example: 11, 22, 33, ?
Logic: Table of 11.
Answer: 44.
28. Alternating Multiplication & Addition
Example: 2, 4, 8, 10, 20, ?
Logic: ×2, +2 alternately.
Answer: 22.
29. Prime Addition
Example: 2, 5, 10, 17, ?
Logic: Add consecutive primes (3, 5, 7…).
Answer: 26.
30. Square Plus Prime
Example: 5, 13, 29, ?
Logic: Square numbers plus primes.
Answer: 53.
31. Multiples of 9
Example: 9, 18, 27, ?
Logic: Table of 9.
Answer: 36.
32. Difference of Squares
Example: 3, 5, 9, 17, ?
Logic: Differences are squares (2, 4, 8…).
Answer: 33.
33. Geometric Progression
Example: 2, 6, 18, 54, ?
Logic: ×3 each time.
Answer: 162.
34. Alternating Division & Multiplication
Example: 64, 32, 96, 48, ?
Logic: ÷2, ×3 alternately.
Answer: 144.
35. Square Plus One
Example: 2, 5, 10, 17, ?
Logic: (n^2 + 1).
Answer: 26.
36. Prime Cubes
Example: 8, 27, 125, ?
Logic: Cubes of primes (2³, 3³, 5³…).
Answer: 343 (7³).
37. Alternating Odd & Even Addition
Example: 10, 13, 17, 22, ?
Logic: +3, +4 alternately.
Answer: 26.
38. Multiplication by 1.5
Example: 4, 6, 9, 13.5, ?
Logic: ×1.5 each time.
Answer: 20.25.
39. Square Minus Prime
Example: 3, 7, 21, 43, ?
Logic: Square numbers minus primes.
Answer: 73.
40. Double & Subtract
Example: 2, 3, 5, 9, 17, ?
Logic: Double previous term −1.
Answer: 33.
Mock Test Practice
Mastering Missing Number Series isn’t just about knowing patterns — it’s about solving them under exam pressure. PracticeMock’s SBI PO mock tests replicate the exact exam environment, pushing you to solve series in 15–30 seconds. With detailed solutions, performance analytics, and timed practice, you’ll sharpen both speed and accuracy. The best way to test your current preparation is to attempt a free mock test today. It will instantly show where you stand and which series types need more revision.
Conclusion
Missing Number Series questions are a scoring opportunity in SBI PO 2026 if you prepare smartly. By practicing the Top 40 types, analyzing differences, cubes, primes, and alternating operations, you’ll build the intuition needed to crack them quickly. Pair this with regular mock test practice, and you’ll be ready to face any tricky series the exam throws at you.
FAQs
Missing Number Series are logical sequences where candidates must identify the missing term using mathematical patterns.
Typically 4–5 questions in the Quant section, but they carry high scoring potential if solved quickly.
Revise cubes, squares, prime differences, and alternating operations. Attempt mock tests to build speed and accuracy.
Yes, they test advanced pattern recognition and logical reasoning, making them crucial for both Prelims and Mains.
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