Bank Exam Speed Maths Master Series – Page 9

Ratio & Proportion Tricks & Fast Calculation Methods

Shaktimatha Learning – Speed Maths Academy
Learn Ratio & Proportion shortcut tricks, aptitude formulas, and fast calculation methods for Bank Exams, SSC, Railways, Insurance, and Competitive Exams.

Importance of Ratio & Proportion in Competitive Exams

Ratio & Proportion is one of the most important topics in:

Bank Exams
SSC
Railway Exams
Insurance Exams
Quantitative Aptitude

This topic is highly useful in:

Partnership
Mixture & Alligation
Ages Problems
Time & Work
Data Interpretation

🎯 What is Ratio?

Ratio compares two quantities.

Example: If A:B = 2:3

It means: For every 2 parts of A, there are 3 parts of B.

Ratio Formula

0

🎯 What is Proportion?

When two ratios are equal, they are said to be in proportion.

Example: 2:4 = 4:8

Proportion Formula

1

Trick 1: Simplify Ratio Quickly

Example: 48 : 72

Find HCF = 24

48 ÷ 24 = 2
72 ÷ 24 = 3

✅ Ratio = 2 : 3

Trick 2: Convert Ratio into Fraction

Example: 3 : 5

Total parts = 3 + 5 = 8

First part:

2

Second part:

3

Trick 3: Find Quantity from Ratio

Example:

Ratio = 2 : 3
Total = 500

Total parts = 5

First quantity:

500 × 2/5 = 200

Second quantity:

500 × 3/5 = 300

✅ Answers = 200 and 300

Trick 4: Direct Proportion Method

If:

Quantity increases
Another quantity also increases

Then: Direct proportion applies.

Formula:

4

Example:

5 pens cost 50
10 pens cost ?

More pens → More cost

50 × 10/5

✅ Answer = 100

Trick 5: Inverse Proportion Method

If:

One quantity increases
Another decreases

Then: Inverse proportion applies.

Example:

10 workers complete work in 12 days
20 workers complete work in ?

Workers increase → Days decrease

10 × 12 = 20 × x

120 = 20x

✅ Answer = 6 days

Componendo & Dividendo Shortcut

If:

5

Then:

6

Useful in advanced aptitude questions.

Important Ratio & Proportion Shortcuts

Topic	Shortcut
Ratio	a:b
Proportion	a/b = c/d
Quantity Division	Ratio parts method
Direct Proportion	Increase → Increase
Inverse Proportion	Increase → Decrease

Practice Questions

Simplify 36 : 54
Divide 600 in ratio 2 : 4
8 books cost 240, find cost of 12 books
15 workers finish work in 20 days, how many days for 30 workers?
Convert ratio 3 : 7 into fractions

✅ Answers

2 : 3
200 and 400
360
10 days
3/10 and 7/10

🎯 Preparation Strategy:
Practice ratio simplification, direct & inverse proportion methods, fraction conversion, and mental calculations daily to improve aptitude speed and quantitative reasoning ability.

“Strong Understanding of Ratios Makes Complex Aptitude Questions Easier.”

MIND GROW Magazine

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