9 original Central Ideas and Details questions, easiest first. The main idea of a passage, or a detail it actually states. Answer them all, then submit once to see every answer explained.
Contrary to the common assumption that ancient Roman concrete was inferior to modern concrete, recent analysis of Roman harbor structures that have survived intact for two thousand years suggests that certain volcanic-ash mixtures used by Roman builders actually grow stronger over time when exposed to seawater.
Which choice best states the main idea of the text?
C — Certain Roman concrete formulations may have durability advantages not found in modern concrete.. The passage directly challenges the assumption of Roman concrete's inferiority, citing evidence that certain mixtures grow stronger over time—choice C captures this central, counterintuitive claim accurately.
Although cinnamon is best known for its flavor and aroma, researchers have found that a specific compound within it appears to help regulate blood sugar levels when consumed regularly, suggesting its potential health benefits may extend beyond its culinary use.
Which choice best states the main idea of the text?
A — Cinnamon may help regulate blood sugar in addition to its known culinary qualities.. The text states a compound in cinnamon 'appears to help regulate' blood sugar, indicating an additional benefit beyond culinary use—matching choice A; choice C contradicts the passage's claim of extended benefits.
The Icelandic sagas, composed centuries after the events they describe, blend historical fact with legend so thoroughly that modern historians must cross-reference archaeological evidence to separate probable fact from embellishment. Even so, many place names and genealogies recorded in the sagas have been independently confirmed, suggesting that oral tradition preserved a surprising amount of accurate detail alongside its more fantastical elements.
Which choice best states the main idea of the text?
C — Despite mixing fact and legend, the sagas preserved some genuinely accurate historical details.. The passage says sagas blend fact and legend, but confirms that some details (place names, genealogies) were independently verified—showing oral tradition preserved real accuracy alongside embellishment, which is choice C.
In the 1950s, computer pioneer Grace Hopper insisted that programming languages should resemble English rather than strings of numbers. Critics called the idea impractical, but her work on the compiler—a program that translates human-readable code into machine instructions—became foundational to modern software.
According to the text, what was significant about Hopper's work on the compiler?
D — It made it possible to translate human-readable code into machine instructions.. The text defines the compiler as 'a program that translates human-readable code into machine instructions'—that is its significance. A and B misstate the passage; C is contradicted by 'critics called the idea impractical.'
A longitudinal study tracking over two thousand adults found that maintaining close friendships in one's thirties predicted better physical health in one's sixties more strongly than exercise habits reported during the same thirties did.
Which choice best states the main idea of the text?
D — Close friendships in midlife were found to be a stronger predictor of later physical health than exercise habits.. The study's finding, stated directly, is that friendships predicted later health 'more strongly than' exercise habits—choice D captures this comparison accurately without overstating it as choice B does.
Interviews conducted with retired professional cyclists revealed that most did not cite crash-related injuries or the physical toll of competition as their primary reason for retiring, but rather a desire to spend more time coaching junior riders after years focused solely on their own racing career.
Which choice best states the main idea of the text?
D — A desire to coach junior riders was the most commonly cited reason for retirement.. The passage explicitly rules out injuries and physical toll as primary causes and instead identifies 'a desire to spend more time coaching junior riders' as the reason—matching choice D precisely.
While solar panel efficiency has roughly doubled over the past two decades, the primary driver of falling solar energy costs has actually been manufacturing scale: as factories produce panels in ever-larger volumes, the cost per unit has dropped far more than efficiency gains alone would predict.
Which choice best states the main idea of the text?
C — Manufacturing scale, more than efficiency gains, has driven down the cost of solar energy.. The passage explicitly attributes falling costs primarily to 'manufacturing scale' rather than efficiency, directly stating efficiency alone would predict smaller cost drops—matching choice C.
While consumer trust in online reviews is often assumed to depend mainly on the review's star rating, several studies have found that the presence of specific, verifiable details in the written text predicts trust far more strongly than star rating alone does.
Which choice best states the main idea of the text?
B — Specific, verifiable detail in review text predicts consumer trust more strongly than star rating alone.. The passage states specific detail 'predicts trust far more strongly than' star rating—the main idea is that detail outweighs rating in determining trust, which is choice B.
Certain species of parrot possess an unusually dense concentration of neurons in a brain region associated with problem-solving, despite having a brain far smaller in overall size than that of many mammals. As a result, these parrots can solve multi-step puzzles and use simple tools at a level comparable to some primates.
Which choice best states the main idea of the text?
D — The parrot's dense neuron concentration is linked to its notable problem-solving abilities.. The passage links dense neuron concentration (a problem-solving-related brain feature) to parrots' documented ability to solve puzzles and use tools—matching choice D directly.
Score:
Every question above is now marked up: the correct answer is highlighted, any wrong option you picked is flagged, and each explanation is open.
No. Every question here is original, written to the College Board's published Digital SAT Reading & Writing specification for the Central Ideas and Details skill. No retired or copyrighted College Board material appears anywhere on this site.
Central Ideas and Details asks either for the main idea of a short passage or for a specific detail the passage states. Both are answered entirely from the text — nothing is inferred, nothing is brought in from outside — but the main-idea version requires the choice to cover the whole passage rather than one part of it.
For a main-idea question, summarise the passage in one sentence before looking at the choices, then eliminate any choice that is true of only one sentence. For a detail question, find the exact line the question points at and match against it word by word — the correct choice paraphrases it, but it never adds to it.
No, and deliberately so. This drill is 9 Central Ideas and Details questions back to back; a real Reading & Writing module is 27 questions in 32 minutes drawn from all eleven skills. Use a drill to fix one weakness, then take a full module to practice the real thing.
No. The SAT has no penalty for a wrong answer — a blank and a wrong guess both score zero — so answer every question, including the ones you have to guess.