Commission scaling with hours and rate: A marketing manager earns ₹240 for a 40-hour week. In the final week, the rate increases by 50% and he works 60 hours. What commission does he earn that week?
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A500
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B540
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C520
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D600
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E480
Answer
Correct Answer: 540
Explanation
Introduction / Context:This item connects hourly pay rate, hours worked, and proportional changes. A percentage increase in rate multiplies the base hourly rate while hours scale total earnings linearly.
Given Data / Assumptions:
- Earnings at base = ₹240 for 40 hours ⇒ base rate = ₹240/40 = ₹6 per hour.
- Rate increases by 50% ⇒ new rate = 1.5 * 6 = ₹9 per hour.
- Final week hours = 60 hours.
Concept / Approach:Total commission = (hourly rate) * (hours). Apply the rate hike first, then multiply by the longer work duration to get the final week’s commission.
Step-by-Step Solution:Base rate = 240 / 40 = ₹6/hNew rate after 50% increase = 6 * 1.5 = ₹9/hCommission = 9 * 60 = ₹540
Verification / Alternative check:Relative scaling: earnings scale by both rate and time. Compared to base, factor = 1.5 (rate) * (60/40) = 1.5 * 1.5 = 2.25. Base week ₹240 * 2.25 = ₹540. Same result.
Why Other Options Are Wrong:500, 520, 600, 480 do not match the exact multiplication of rate and hours given by the scenario.
Common Pitfalls:Adding 50% of weekly earnings and then scaling hours, instead of adjusting the hourly rate first and then multiplying by hours.
Final Answer:540