Number System Practice & Questions
Number System is the core theoretical domain testing divisibility properties, cyclicity of powers, and prime factorization.
Core Concepts in Number System
Questions from this topic consistently evaluate the following core principles across SSC, Railways, and Banking papers:
- Divisibility rules (7, 11, 13, 72, 88)
- Cyclicity and unit digit of powers
- Euler's and Fermat's remainder theorems
- Total number of factors and sum of factors
- Trailing zeroes in factorials
Exam Speed Strategy & Shortcuts
- For divisibility by 72, check divisibility by both 8 and 9 independently.
- Identify powers of 5 to determine trailing zeroes in factorials.
Exams Testing Number System
Mastering this topic directly contributes to clearing cutoffs in these examinations: