Weekly Challenge
Five original questions for the week of September 7, 2026. No timer. Check each answer as you go.
A study of 500 office workers found that those with sit-stand desks reported 30 percent less back pain. The researchers conclude that sit-stand desks reduce back pain.
Which of the following, if true, most strengthens the conclusion?
Random assignment rules out the alternative that healthier people chose the fancy desks. That is what turns a correlation into evidence of cause.
If the train is on time, Priya will make her connection. Priya missed her connection.
Which of the following follows logically?
If P then Q. Not Q. Therefore not P. The missed connection proves the train was late (at least under the stated rule).
Switching the office to a four-day week will not hurt output, because employees will work the same total hours compressed into four days.
The argument depends on the assumption that
Same total hours only means same output if each hour is as productive. If longer days tire people out, output drops even with equal hours.
You claim raising the minimum wage always kills jobs. But the city of Lakeview raised its minimum wage twice in the last decade, and employment grew both times. Your general claim is false.
The argument uses which method?
One solid counterexample kills an "always" claim. Lakeview is presented as exactly that: a case where the rule failed.
The new traffic cameras will make intersections safer, because drivers slow down when they know they are being watched.
Which of the following, if true, most weakens the argument?
If cameras just move the danger down the road, intersections are not actually safer. The mechanism the argument relies on backfires.
A free diagnostic shows your starting score, then a study plan tells you what to work on next.
Last updated October 12, 2026