Ratio: Concept, Properties & Business Distribution
1. Meaning & Commercial Definition of Ratio
A ratio is a relationship between two numbers or quantities of the same kind, expressing how many times one contains or is contained within the other. It is written as a : b (read as “a is to b”), or as the fraction a / b:
- The first quantity a is called the Antecedent.
- The second quantity b is called the Consequent (b ≠ 0).
Fundamental Operational Properties of Ratios:
- Unitless Dimension: A ratio is a pure number; it carries no physical unit of measurement.
- Homogeneity of Units: Quantities compared must be converted into the identical unit before computing the ratio (e.g., comparing 50 paise to ₹2 requires converting ₹2 to 200 paise, yielding 50 : 200 = 1 : 4).
- Invariance under Multiplication/Division: Multiplying or dividing both antecedent and consequent by the same non-zero constant does not alter the value:
(a × k) : (b × k) = a : b (k ≠ 0)
2. Taxonomy of Special Mathematical Ratios
Common Variants of Mathematical Ratios
1. Duplicate Ratio
Ratio of the squares of original terms:
a² : b²
Example: Duplicate ratio of 3 : 4 is 3² : 4² = 9 : 16.
a² : b²
Example: Duplicate ratio of 3 : 4 is 3² : 4² = 9 : 16.
2. Sub-Duplicate Ratio
Ratio of the square roots of original terms:
√a : √b
Example: Sub-duplicate ratio of 25 : 49 is √25 : √49 = 5 : 7.
√a : √b
Example: Sub-duplicate ratio of 25 : 49 is √25 : √49 = 5 : 7.
3. Triplicate Ratio
Ratio of the cubes of original terms:
a³ : b³
Example: Triplicate ratio of 2 : 3 is 2³ : 3³ = 8 : 27.
a³ : b³
Example: Triplicate ratio of 2 : 3 is 2³ : 3³ = 8 : 27.
4. Inverse / Reciprocal Ratio
Interchanging antecedent and consequent:
b : a (or 1/a : 1/b)
Example: Inverse of 4 : 7 is 7 : 4.
b : a (or 1/a : 1/b)
Example: Inverse of 4 : 7 is 7 : 4.
3. Commercial Applications: Division in Given Ratio
In corporate partnerships, profits, losses, or assets are distributed in proportion to capital invested and time duration:
Problem 1: Partnership Profit Sharing
Question: A, B, and C invest ₹50,000, ₹75,000, and ₹1,25,000 respectively in a commercial venture. At the end of the financial year, the net profit is ₹72,000. Distribute the profit among the three partners.
Step-by-Step Solution:
- Determine the capital investment ratio:
A : B : C = 50,000 : 75,000 : 1,25,000- Divide through by 25,000:
A : B : C = 2 : 3 : 5
- Sum of the ratio terms:
2 + 3 + 5 = 10
- Compute each partner’s share:
- A’s Share: (2 ÷ 10) × ₹72,000 = ₹14,400
- B’s Share: (3 ÷ 10) × ₹72,000 = ₹21,600
- C’s Share: (5 ÷ 10) × ₹72,000 = ₹36,000
- Verification:
14,400 + 21,600 + 36,000 = ₹72,000(Exact match with total profit!)