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 early sailing ships relied solely on the wind blowing directly from behind, historical analysis of ship logs and hull designs shows that skilled crews as early as the medieval period could sail at an angle against the wind using a technique called tacking.
Which choice best states the main idea of the text?
A — Medieval sailors had developed techniques allowing ships to sail effectively against the wind.. The passage directly challenges the assumption of wind-only sailing, citing evidence that medieval crews could tack against the wind—choice A captures this central, counterintuitive claim accurately.
A workplace study found that employees who received specific, actionable feedback from managers ('revise the third paragraph to include supporting data') improved their performance more over three months than employees who received only general praise or general criticism without specific suggestions.
Which choice best states the main idea of the text?
A — Specific, actionable feedback was found to improve performance more than general praise or criticism.. The passage directly states specific feedback led to greater improvement 'than employees who received only general praise or general criticism'—matching choice A; choice D contradicts this finding.
Certain species of moth possess ears located not on their heads but on their abdomens, an unusual placement that nonetheless allows them to detect the high-frequency echolocation calls of hunting bats from significant distances. As a result, these moths can begin evasive flight maneuvers well before a bat is close enough to catch them.
Which choice best states the main idea of the text?
D — The unusual placement of the moth's ears allows it to detect and evade approaching bats early.. The passage links the unusual abdominal ear placement to the moth's documented ability to detect bats early and begin evasive maneuvers—matching choice D directly.
While battery capacity in electric scooters has roughly doubled over the past five years, the primary driver of their increased range has actually been improvements in regenerative braking systems, which recover energy during braking far more efficiently than capacity increases alone would predict.
Which choice best states the main idea of the text?
B — Regenerative braking improvements, more than battery capacity, have driven the increase in electric scooter range.. The passage explicitly attributes increased range primarily to braking system improvements rather than battery capacity, directly stating capacity alone would predict smaller range gains—matching choice B.
Although green tea is best known for its antioxidant content, researchers have found that a specific compound within it also appears to improve the brain's ability to form new neural connections when consumed regularly over several months, suggesting its cognitive benefits may extend well beyond antioxidant effects.
Which choice best states the main idea of the text?
D — Green tea may aid the formation of new neural connections in addition to its known antioxidant effects.. The text states green tea's compound 'also appears to improve' neural connection formation, indicating an additional benefit beyond antioxidants—matching choice D; choice C contradicts the passage's claim of extended benefits.
A longitudinal study tracking over four thousand adults found that maintaining a consistent sleep schedule in one's twenties predicted better cardiovascular health in one's fifties more strongly than average sleep duration during the same period did.
Which choice best states the main idea of the text?
B — A consistent sleep schedule in early adulthood was found to be a stronger predictor of later cardiovascular health than sleep duration.. The study's finding, stated directly, is that schedule consistency predicted later cardiovascular health 'more strongly than' sleep duration—choice B captures this comparison accurately without overstating it as choice A does.
Although ginger is best known for easing nausea, researchers have found that a specific compound within it also appears to reduce exercise-induced muscle soreness when consumed regularly over several weeks, suggesting its physical benefits may extend beyond its well-known digestive effects.
Which choice best states the main idea of the text?
C — Ginger may help reduce muscle soreness in addition to its known digestive benefits.. The text states a compound in ginger 'also appears to reduce' muscle soreness, indicating an additional benefit beyond digestive effects—matching choice C; choice D contradicts the passage's claim of extended benefits.
While wind turbine blade length has roughly tripled over the past three decades, the primary driver of falling wind energy costs has actually been improvements in predictive maintenance software, which reduces costly unplanned downtime far more than blade length increases alone would predict.
Which choice best states the main idea of the text?
A — Predictive maintenance software, more than blade length, has driven down the cost of wind energy.. The passage explicitly attributes falling costs primarily to maintenance software rather than blade length, directly stating blade length alone would predict smaller cost drops—matching choice A.
While tipping in restaurants is often assumed to be primarily a reward for attentive service, several studies have found that a customer's own mood upon arrival—shaped by factors like traffic on the drive over or an earlier stressful meeting—predicts tip size more strongly than measured service quality does.
Which choice best states the main idea of the text?
A — A customer's pre-existing mood often influences tip size more than the service they actually receive.. The passage states that customer mood 'predicts tip size more strongly than' service quality—the main idea is that mood outweighs service in determining tips, which is choice A.
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.