In a partnership, A invests $\frac{1}{6}$ of the capital for $\frac{1}{6}$ of the time, B invests $\frac{1}{3}$ of the capital for $\frac{1}{3}$ of the time and C, the rest of the capital for the whole time. Out of a profit of ₹ 4600, B's share is (M.B.A., 2004)
Aptitude
Partnership
Difficulty: Medium
Choose an option
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A₹ 650
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B₹ 800
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C₹ 960
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D₹ 1000
Answer
Correct Answer: ₹ 800
Explanation
### Concept & Fractional Investment Proportions
When investments and time periods are given as fractions of a whole, multiply the capital fraction by the time fraction for each partner to establish the unsimplified profit ratio, then clear the denominators.
### Step-by-Step Solution
* Let total capital be $1$ unit and total time be $1$ unit.
* **A's Investment Profile:**
* Capital = $\frac{1}{6}$
* Time = $\frac{1}{6}$
* Product = $\frac{1}{6} \times \frac{1}{6} = \frac{1}{36}$
* **B's Investment Profile:**
* Capital = $\frac{1}{3}$
* Time = $\frac{1}{3}$
* Product = $\frac{1}{3} \times \frac{1}{3} = \frac{1}{9}$
* **C's Investment Profile:**
* Capital = Rest of the capital = $1 - (\frac{1}{6} + \frac{1}{3}) = 1 - (\frac{1}{6} + \frac{2}{6}) = 1 - \frac{3}{6} = \frac{1}{2}$
* Time = Whole time = $1$
* Product = $\frac{1}{2} \times 1 = \frac{1}{2}$
* **Profit Ratio:**
* $A : B : C = \frac{1}{36} : \frac{1}{9} : \frac{1}{2}$
* Multiply by LCM (36) to clear fractions:
* $1 : 4 : 18$
* **B's Share:**
* Total ratio parts = $1 + 4 + 18 = 23$
* Total profit = ₹ 4600
* B's share = $\frac{4}{23} \times 4600 = 4 \times 200 = 800$
### Exam Strategy & Shortcut
To avoid fractions entirely, assume a total capital and total time that are easily divisible by the denominators (6 and 3). Let Total Capital = 6 and Total Time = 6. A: $1 \times 1 = 1$. B: $2 \times 2 = 4$. C: remaining capital (3) $\times$ whole time (6) = 18. The ratio $1 : 4 : 18$ is found instantly.
### Common Pitfall
Incorrectly calculating C's remaining capital by forgetting to subtract both A's and B's shares from the total whole (1).
### Final Answer
Therefore, the correct answer is **₹ 800**.