2025 CSAT — Q4
Passage
The history of renewable energy suggests there is a steep learning curve, meaning that, as more is produced, costs fall rapidly because of economies of scale and learning by doing. The firms’ green innovation is path-dependent: the more a firm does, the more it is likely to do in the future. The strongest evidence for this is the collapse in the price of solar energy, which became about 90% cheaper during the 2010s, repeatedly beating forecasts. Moving early and gradually gives economies more time to adjust, allowing them to reap the benefits of path-dependent green investment without much disruption. A late, more chaotic transition is costlier.
With reference to the above passage, the following assumptions have been made:
I. Path-dependent green investments will eventually most likely benefit growth as well as public finances in a country like India.
II. If other green technologies follow the same pattern as that of solar energy, there will most likely be an easy green transition.
Which of the above assumptions is/are valid?
Thinking pathway
Locate. This is a valid-assumption question, so find the argument’s load-bearing leap — the place where the passage moves from what it shows to what it concludes. Here the leap is explicit in structure: solar is offered as “the strongest evidence,” and from it the author concludes that moving early into green investment pays off “without much disruption.” A single example carrying a general conclusion is the signature of a hidden generalising assumption.
Test (the negation test). Negate each candidate. Statement II = “if other green tech follows the solar pattern, transition is easy.” Negate it — suppose other green tech does not follow solar — and the passage’s optimistic generalisation collapses. So II is exactly the bridge the argument can’t do without: valid. Statement I bolts on “India” and “public finances,” neither in the text; negating I leaves the argument untouched, so I was never assumed: invalid.
Eliminate by anatomy. (a) makes a claim the passage never actually makes — it picks the statement that adds particulars (India, public finances) a reader supplies from the world, and misses the real assumption. (c) is half right, half wrong — it correctly spots II but wrongly admits the unsupported I. (d) is a step the text doesn’t license — it over-rejects, failing to see that arguing from one example to a general claim is an assumption. The transferable move: the valid assumption is the bridge the argument cannot do without, never the detail that merely sounds informed. Key: (b).
Evidence in the text
The passage generalises from solar (“the strongest evidence”) to the broader claim that early, path-dependent green investment is reaped “without much disruption” — this argument PRESUMES the solar pattern generalises to green tech broadly, which is exactly Statement II. Statement I imports “India” and “public finances,” neither of which the passage mentions.
Worked rationale
Apply the negation test to each candidate assumption — the one the passage’s argument needs.
Statement I — “…benefit growth as well as public finances in a country like India.” The passage speaks of “economies” and “firms” in general and never mentions India or public finances. The argument stands without this specific claim, and it adds two concepts (India, public finances) the text never introduces. I is invalid — a claim the passage never actually makes.
Statement II — “If other green technologies follow the same pattern as solar, there will most likely be an easy green transition.” This is the hinge of the passage. The author offers solar as “the strongest evidence” and then generalises — concluding that moving early and gradually yields benefits “without much disruption.” That generalisation only works if the solar pattern extends to green technologies generally. Negate II (suppose other green tech does not follow the solar pattern) and the passage’s optimistic conclusion collapses. So II is exactly the unstated premise the argument leans on. II is valid.
Answer: (b) II only.
Why the other options miss
- A a claim the passage never actually makes: picks the statement that adds India + public finances, neither in the passage, and misses the genuine generalising assumption (II).
- C half right, half wrong: correctly spots II but wrongly admits the unsupported I.
- D a step the text doesn’t license: over-rejects; fails to see that the passage’s leap from solar to green tech generally is an assumption, making II valid.
Specialist insight
This is the hard item of the block and it turns on one move: a passage that argues from a single example (solar) to a general claim (green investment pays off) is assuming the example generalises. That hidden generalisation is the assumption — Statement II names it exactly. The trap (I) is a textbook case of introducing something the passage never mentions: it bolts on plausible, specific particulars (“India,” “public finances”) that a reader supplies from the world. The discipline: the valid assumption is the bridge the argument cannot do without, not the detail that merely sounds informed.
I bolts on particulars the passage never mentions (India, public finances); II is the example-to-general bridge the argument can't do without — (b).