Weekly Challenge
Five original questions for the week of August 31, 2026. No timer. Check each answer as you go.
A new energy drink claims to improve focus because it contains 200 mg of caffeine, and caffeine is known to increase alertness.
Which of the following, if true, most weakens the claim?
The claim leans on caffeine helping focus. If this dose of caffeine actually hurts focus, the evidence turns against the claim.
People say they want honest politicians, then punish candidates who admit mistakes. Until voters reward honesty instead of punishing it, campaigns will keep hiding flaws. So the dishonesty voters complain about is partly their own doing.
The main conclusion of the argument is that
The final sentence states the point: voters help cause the dishonesty they complain about. The rest explains the mechanism.
The restaurant will earn a profit this year. It earned a profit last year, and nothing important has changed.
Which of the following, if assumed, allows the conclusion to follow logically?
B turns the argument into a valid deduction: the restaurant fits the rule exactly, so the conclusion is guaranteed. The rest only make it plausible.
Lena: "The school should start classes at 9 a.m. because teenagers learn better with more sleep." Marco: "Starting at 9 would force after-school programs to end too late, so the school should keep the 8 a.m. start."
Lena and Marco disagree about whether
Lena argues for the change; Marco argues against it. That is the direct point of disagreement. They never dispute sleep science (A, E).
Our rival's software must be insecure. Their CEO was once fined for insider trading, so you cannot trust anything their company makes.
The argument commits which flaw?
The CEO's past has nothing to do with the software's security. This is a classic ad hominem: attack the person, dodge the issue.
A free diagnostic shows your starting score, then a study plan tells you what to work on next.
Last updated October 12, 2026