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04 Sep 2025, 15:30
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It looks as though you've missed one critical detail: "a single LED bulb costs much more than five CFL bulbs." So the CFLs should be much more cost efficient already. I hope that clears it up!
For more on (B), check out this post: https://gmatclub.com/forum/compact-fluo ... l#p2772664.
05 Sep 2025, 01:39
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Great analytical thinking! Let me help you work through the logical issue in your reasoning.
Step 1: Understanding Your Calculation
Your math shows:
LED efficiency: (\frac{50,000 \text{ hours}}{100 \text{ cost}} = 500) hours per unit cost
CFL efficiency: (\frac{10,000 \text{ hours}}{20 \text{ cost}} = 500) hours per unit cost
The Key Issue with Your Logic
Your calculation actually proves that LED and CFL are equally cost-efficient - both give 500 hours per cost unit. But then you conclude CFL needs to get cheaper to compete. This creates a contradiction!
If they're already equally efficient by your calculation, why would CFL need to drop prices to compete?
Step 2: What the Passage Actually Tells Us
The passage states: "a single LED bulb costs much more than five CFL bulbs"
Since LED lasts 5× longer than CFL, if LED costs more than 5× the price, then LED is actually less cost-efficient than CFL on a per-hour basis.
Step 3: The Real Competitive Dynamic
- CFL is already more cost-effective per hour of light
- LED's advantage isn't cost efficiency - it's longevity
This longevity becomes valuable in specific situations
Step 4: Why Answer A Makes Sense
LED would be preferred where replacement difficulty/cost matters more than upfront cost efficiency:
- Hard-to-reach fixtures
- Industrial/commercial settings
- Locations where changing bulbs is expensive/disruptive
Strategic Takeaway: In Critical Reasoning, always check if your mathematical analysis supports your conclusion. Here, the passage suggests LED is less cost-efficient but more convenient - leading us to consider where convenience trumps cost efficiency.
Answer: A
Step 1: Understanding Your Calculation
Your math shows:
LED efficiency: (\frac{50,000 \text{ hours}}{100 \text{ cost}} = 500) hours per unit cost
CFL efficiency: (\frac{10,000 \text{ hours}}{20 \text{ cost}} = 500) hours per unit cost
The Key Issue with Your Logic
Your calculation actually proves that LED and CFL are equally cost-efficient - both give 500 hours per cost unit. But then you conclude CFL needs to get cheaper to compete. This creates a contradiction!
If they're already equally efficient by your calculation, why would CFL need to drop prices to compete?
Step 2: What the Passage Actually Tells Us
The passage states: "a single LED bulb costs much more than five CFL bulbs"
Since LED lasts 5× longer than CFL, if LED costs more than 5× the price, then LED is actually less cost-efficient than CFL on a per-hour basis.
Step 3: The Real Competitive Dynamic
- CFL is already more cost-effective per hour of light
- LED's advantage isn't cost efficiency - it's longevity
This longevity becomes valuable in specific situations
Step 4: Why Answer A Makes Sense
LED would be preferred where replacement difficulty/cost matters more than upfront cost efficiency:
- Hard-to-reach fixtures
- Industrial/commercial settings
- Locations where changing bulbs is expensive/disruptive
Strategic Takeaway: In Critical Reasoning, always check if your mathematical analysis supports your conclusion. Here, the passage suggests LED is less cost-efficient but more convenient - leading us to consider where convenience trumps cost efficiency.
Answer: A
13 Sep 2025, 21:02
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option C - Accidental breakages would affect both LED's as well as CFL's equally
