'Net Effect' Method: 2 years r% pe, effective rate = r + r + (r×r)/100. Example: 10% do saal → 10+10+1 = 21% effective. Principal pe ek baar lagao.
Compound Interest Shortcut Method
SSCBankingCATClass 10
Yaad Karne ki List
- 2-year CI shortcut: CI = P × [(1+r)² - 1]
- 2 years effective rate: 2r + r²/100
- CI-SI difference 2 years = P × (r/100)²
- 3-year CI = P × [(1+r)³ - 1]
- Population growth: P(1+r/100)ⁿ
- Depreciation: P(1-r/100)ⁿ
Mnemonic Tricks
Kaise Map Hota Hai
| Cue | Maps To |
|---|---|
| r + r + r²/100 | Effective 2-year rate |
| Effective rate × P | CI directly mil jaata hai |
| CI - SI = P(r/100)² | 2 year quick difference |
Yeh Fast Kyun Hai
Year 1, phir year 2 separately calculate karne ke bajaye, ek multiplication se answer. 10% pe 2 years ₹1000 pe: effective = 21%, CI = ₹210. Done in 5 seconds.
Aksar Poochhe Jaane Wale Sawaal
2 year ka compound interest shortcut kya hai?
Effective rate method: r% rate 2 years ke liye, effective rate = 2r + r²/100. Principal ko is rate se multiply karo. Example: 10% → 21% → ₹5000 pe CI = ₹1050.
CI-SI difference jaldi kaise nikaalein?
2 years: CI - SI = P × (r/100)². 3 years: CI - SI = P × r² × (300+r) / 1000000. One-step formulas.
Mentally CI kaise calculate karein?
Net effect: rates add karo aur unka product/100. 10% over 2 years: 10+10+1 = 21%. 20% over 2 years: 20+20+4 = 44%.
Kya CI SSC aur Banking mein pucha jaata hai?
Bahut pucha jaata hai. SSC CGL, CHSL aur sabhi banking exams mein 3-5 questions per paper. Shortcuts 30-60 seconds save karte hain.