Number Series: 20 Common Patterns You Must Know for Banking Exams

Number series carries 5 marks in Prelims and appears in DI sets too. Knowing common patterns helps you solve these in seconds.

Most Common Patterns

1. Prime number series: Differences are prime numbers (2, 3, 5, 7, 11...). 2. Square/Cube series: 1, 4, 9, 16, 25... or 1, 8, 27, 64... 3. Mixed operations: ×2+1, ×2+3, ×2+5... (multiplier constant, adder changes). 4. Alternating operations: +5, ×2, +5, ×2... 5. Fibonacci-type: Each number is sum of previous two.

Wrong Number Series

For wrong number series, check each pair of consecutive numbers. Apply the suspected pattern and find which number breaks it. The wrong number is usually the 3rd or 4th term.

Speed Tip

First check differences. If differences don't show a pattern, check ratios. If ratios don't work, check differences of differences (second-level differences). 90% of series can be solved within these three checks.