The income of Amala is more than that of Bimala and less than that of Kamala. If Kamala's income goes down by and Bimala's goes up by , then the percentage by which Kamala's income would exceed Bimala's is nearest to
The income of Amala is more than that of Bimala and less than that of Kamala. If Kamala's income goes down by and Bimala's goes up by , then the percentage by which Kamala's income would exceed Bimala's is nearest to
Solution
We need to find how much more Kamala earns compared to Bimala after both their incomes change. We'll work with the relationships given systematically.
We assume Bimala's income = Rs. 100
When dealing with percentage problems, assuming one value as 100 makes calculations much easier. Since we're looking for percentage differences, the actual amounts don't matter - only the ratios between them.
Amala earns 20% more than Bimala
Amala's income = 100 + 20% of 100 = 100 + 20 = Rs. 120
Amala earns 20% less than Kamala
This means: Amala = Kamala - 20% of Kamala = 0.80 × Kamala
So: 120 = 0.80 × Kamala
Therefore: Kamala = 120 ÷ 0.80 = Rs. 150
Quick Check: 20% of 150 = 30, so 150 - 30 = 120
Bimala's income goes up by 10%
New income = 100 + 10% of 100 = 100 + 10 = Rs. 110
Kamala's income goes down by 4%
New income = 150 - 4% of 150 = 150 - 6 = Rs. 144
When we want to find by what percentage A exceeds B:
Since the question asks for the nearest percentage, 31% is our answer.
When solving percentage comparison problems:
- Assume convenient values (like 100) for easier calculation
- Work step-by-step through each relationship
- Always verify your intermediate results
- Use the standard formula for percentage excess:
Answer: 31%