CSAT › Quantitative Aptitude
Revision note: Number System
- Remainder of product = product of remainders (then reduce)
- Unit digit cycles: 2,3,7,8 → 4; 4,9 → 2; 0,1,5,6 → 1
- Factors of a^p b^q = (p+1)(q+1)
- Σn = n(n+1)/2; Σodd = n²
Source: https://upscprep.in/upsc/csat/quantitative-aptitude/number-system/ · UPSCPrep.in