A sum of money is divided among 160 males and some females in the ratio 16 : 21. Individually each male gets ₹ 4 and a female ₹ 3. The number of females is
Aptitude
Ratio and Proportion
Difficulty: Easy
Choose an option
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A198
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B270
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C280
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D284
Answer
Correct Answer: 280
Explanation
### Concept & Ratio of Totals vs Individuals
The total amount received by a group is the product of the number of individuals in that group and the amount each individual receives.
$$\text{Total Amount for Group} = \text{Number of People} \times \text{Amount per Person}$$
### Step-by-Step Solution
1. **Given:**
- Number of males = 160
- Amount per male = ₹ 4
- Amount per female = ₹ 3
- Ratio of total male money to total female money = $16 : 21$
2. **Calculate Total Male Amount:**
Total money received by all males = $160 \times 4 = 640$.
3. **Use Ratio to Find Total Female Amount:**
Let total male money be $16x$ and total female money be $21x$.
$16x = 640 \implies x = 40$.
Total money received by all females = $21x = 21 \times 40 = 840$.
4. **Calculate Number of Females:**
Since each female gets ₹ 3, the number of females is:
$$\text{Number of Females} = \frac{\text{Total Female Money}}{\text{Amount per Female}} = \frac{840}{3} = 280$$
### Exam Strategy & Shortcut
Set up a single proportion equation:
$\frac{\text{Total Male Money}}{\text{Total Female Money}} = \frac{160 \times 4}{F \times 3} = \frac{16}{21}$.
Solve for $F$: $\frac{640}{3F} = \frac{16}{21} \implies 16 \times 3F = 640 \times 21 \implies 48F = 13440 \implies F = 280$.
### Common Pitfall
Confusing the ratio of total money with the ratio of individuals. Always differentiate between total pool ratios and per-head ratios.
### Final Answer
Therefore, the correct answer is **280**.