Ratio and Proportion
SSC GD Exam Preparation - Quantitative Aptitude
1. What is a Ratio?
A ratio is a comparison between two quantities of the same kind.
Ratio = a/b or a : b
Example: Boys : Girls
→ 3 : 2
Example: Speed A : Speed B
→ 40 : 60 = 2 : 3
Example: Rs 50 : Rs 100
→ 50 : 100 = 1 : 2
2. Simplifying a Ratio
Rule: Divide both terms by their HCF
Example: Simplify 20 : 30
HCF of 20 and 30 = 10
20 ÷ 10 : 30 ÷ 10
→ 2 : 3
3. Equivalent Ratios
Multiply or divide both terms by the same number
3 : 4
6 : 8
9 : 12
All represent the same ratio
4. Comparing Ratios
Convert ratios into fractions for comparison
Example: Which is greater: 3 : 5 or 4 : 7?
3/5 = 0.6
4/7 ≈ 0.571
→ 3 : 5 is greater
5. Ratio in Real-Life Problems
(a) Sharing/Distribution
If Rs 900 is divided in ratio 2 : 1
Total parts = 2 + 1 = 3
Each part = 900 ÷ 3 = 300
Person 1 = 2 × 300 = 600
Person 2 = 1 × 300 = 300
(b) Finding a Missing Value
If a : b = 4 : 5 and a = 24
4 → 24
→ 1 = 6
→ b = 5 × 6 = 30
(c) Ratio Between Three Quantities
A : B = 2 : 3 and B : C = 4 : 5
A : B = 2 : 3 → multiply by 4 → 8 : 12
B : C = 4 : 5 → multiply by 3 → 12 : 15
Final Ratio: A : B : C = 8 : 12 : 15
6. Important Points for SSC GD
Ratios have no units
Both quantities must be of the same type
Always simplify the ratio
Order matters: 3 : 4 ≠ 4 : 3
Practice unit conversion for time, money, etc.
7. Quick Recap
| Concept | Key Point |
|---|---|
| Ratio Definition | Comparison of two quantities |
| Simplification | Divide by HCF |
| Equivalent Ratios | Multiply/divide by same number |
| Comparison | Convert to fractions |
| Distribution | Sum of parts × value per part |
| Three Quantities | Make common term equal |
8. Practice Questions for SSC GD
Test your ratio concepts with these SSC GD level practice questions. Click on "View Answer" to check your understanding.
Q1. Simplify 42 : 70
View Answer
3 : 5
Q2. 3 : 9 is equal to?
View Answer
1 : 3
Q3. If a : b = 4 : 5 and a = 20, find b.
View Answer
25
Q4. Which ratio is larger: 5 : 8 or 7 : 12?
View Answer
5 : 8 (0.625 > 0.583)
Q5. Divide Rs 600 in the ratio 2 : 3.
View Answer
240, 360
Q6. If the ratio of boys to girls = 7 : 5 and there are 35 boys, find girls.
View Answer
25
Q7. Simplify 16 : 24 : 40.
View Answer
2 : 3 : 5
Q8. If A : B = 3 : 4 and B : C = 2 : 5, find A : B : C.
View Answer
3 : 4 : 10
Q9. Convert 0.5 : 1.5 into a simple ratio.
View Answer
1 : 3
Q10. Ratio of ages of A and B is 5 : 7. If A is 20, find B.
View Answer
28
Q11. Find the ratio of Rs 75 to Rs 300.
View Answer
1 : 4
Q12. If a : b = 6 : 11, find (a + b) : b.
View Answer
17 : 11
Q13. A sum of Rs 900 is divided in ratio 3 : 2. Find share of larger part.
View Answer
540
Q14. Find the ratio of 2 hours to 30 minutes.
View Answer
Convert 2 hours = 120 min → 120 : 30 = 4 : 1
Q15. Find the missing term: 8 : ? = 4 : 1
View Answer
2
✅ SSC GD Exam Strategy
🟢 Practice quick ratio simplification using HCF method
🟢 Master unit conversion for time, money, and measurements
🟢 Learn to solve three quantity ratios quickly
🟢 Practice distribution problems - common in SSC GD
🟢 Time yourself - aim for 45-60 seconds per ratio question
You've completed Ratio & Proportion Concepts!
SSC GD Tip: Ratio and Proportion is a high-scoring topic in the quantitative section. Focus on mastering the basic concepts first, then practice application-based problems. Remember to always simplify ratios, convert units when necessary, and verify your answers by checking if the ratios maintain their proportionality. Regular practice with previous year SSC GD questions will build your speed and accuracy.
Master Ratio & Proportion for SSC GD Exam!
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