Practice Test 1 - LSAT Logical Reasoning

20 questions. Answer them in any order, then submit to see your score and every explanation.

Start practice test

1. The argument proceeds by
2. A city opened a new bike lane on a busy avenue. In the three months afterward, the number of reported bicycle accidents on that avenue fell by 40% compared to the three months before. Because the speed limit and traffic signals were unchanged, a council member concludes that the bike lane made cycling safer. Therefore, building bike lanes on all major avenues will reduce bicycle accidents citywide by a similar percentage, and the reduction will continue as more people choose to commute by bike. Which one of the following, if true, most strengthens the argument?
3. A city councilor argues: Whenever a neighborhood's streets are well lit at night, reports of car break-ins are low. The Oakview neighborhood has just completed an upgrade that makes its streets well lit at night. Therefore, car break-ins in Oakview will be low. The councilor admits that Oakview has also increased police patrols, but maintains that the lighting upgrade alone supports the prediction. The reasoning above conforms most closely to which one of the following principles?
4. A nutrition blogger argues that a certain cereal is unhealthy. The blogger notes that any food containing more than 15 grams of added sugar per serving should be classified as unhealthy. The cereal's label lists 18 grams of added sugar per serving. Therefore, the cereal should be classified as unhealthy, and thus consumers should avoid it. The argument assumes that consumers should avoid any food that is properly classified as unhealthy. Which one of the following, if assumed, allows the conclusion of the argument to be properly drawn?
5. The conclusion follows logically if which one of the following is assumed?
6. The argument's reasoning is most vulnerable to criticism on the grounds that it
7. Which one of the following, if true, provides the most support for the conclusion above?
8. A fitness app company reports that the average number of workouts logged per user increased over the past six months. Yet the company also reports that total time spent in the app per user decreased, and that fewer users opened the app more than once per day. In user interviews, many people said the app felt "less engaging" than before. These facts appear difficult to reconcile, since more workouts logged would seem to require more app usage and engagement. Which one of the following, if true, most helps to resolve the apparent discrepancy described above?
9. A nonprofit organization reports that donations from individual donors increased this year. Yet it also reports that the number of individual donors decreased, and that it spent less on fundraising events. Several long-time volunteers say they saw fewer new faces at the organization's activities. These facts seem hard to reconcile, since fewer donors, less fundraising, and fewer new participants would seem likely to reduce individual donations rather than increase them. Which one of the following, if true, most helps to explain the situation described above?
10. Which of the following best describes how the argument proceeds?
11. Which one of the following principles, if valid, most justifies the airline's action?
12. A homeowner installed a smart thermostat and noticed that her monthly heating bill dropped by about 12% compared with the previous winter. She also found herself adjusting the temperature less often because the thermostat learned her schedule. Since smart thermostats optimize heating patterns, installing one reduces energy use. Therefore, if most households in the region install smart thermostats, regional energy demand in winter will drop significantly. Which one of the following, if true, most weakens the argument?
13. Which one of the following assumptions permits the conclusion above to be properly drawn?
14. A nutrition blogger claims that drinking green tea every morning causes weight loss. In a survey of her readers, those who reported drinking green tea daily also reported losing more weight than those who did not. But the tea drinkers were far more likely to report exercising at least four times per week. Since exercise is known to promote weight loss, the blogger's survey does not establish that green tea causes weight loss. The statement that the tea drinkers were far more likely to report exercising at least four times per week plays which one of the following roles in the argument?
15. A tech company manager concludes that a recent security alert indicates an actual intrusion. The manager notes that if an employee's credentials are used from two countries within one hour, then either there was an intrusion or the employee was using the company's VPN. The manager also notes that the alert involved credentials used from two countries within one hour, and that the employee was not using the company's VPN. Therefore, there was an intrusion. Which one of the following assumptions, if made, enables the conclusion to be properly drawn?
16. During a staff meeting, a manager argued: Last quarter, our customer-support tickets were resolved faster on days when the team used the new triage checklist. Also, the checklist does not add any steps to the process; it merely orders existing steps. Finally, whenever a work tool improves speed without increasing workload, adopting it companywide is the sensible choice. Therefore, we should require every support team, not just ours, to use the new triage checklist. The reasoning above most closely conforms to which one of the following principles?
17. A journal editor adopts this principle for issuing corrections: A correction should be published only when an error affects the interpretation of the results or the accuracy of a key fact (such as a date, quantity, or attribution). Minor typographical errors that do not affect interpretation should not prompt a formal correction. The editor uses this principle to decide which reported mistakes warrant a correction notice. Which one of the following situations is most consistent with the principle stated above?
18. At a city library, administrators report that total in-person visits this year are 15 percent higher than last year. Yet a separate internal report says that the average number of visitors present in the building at any given time during open hours has dropped noticeably, and staff members say the reading rooms feel less crowded most afternoons. Both reports are said to be based on accurate counts rather than estimates, and the library's hours of operation have not changed since last year. Which one of the following, if true, most helps to resolve the apparent discrepancy in the information above?
19. The argument's pattern of reasoning is most accurately described as
20. A city has installed new traffic lights at several intersections to reduce accidents. Preliminary data shows a 15% decrease in accidents at these locations. However, the data also shows an overall increase in traffic volume in the city during this period. The city council concludes that the new traffic lights are responsible for the reduction in accidents. Which one of the following would be most useful to know in evaluating the city council's conclusion?

Practice tests