Inference

The premises state that either the witness lied or the report is wrong, and then affirm that the report is correct; by disjunctive syllogism the remaining alternative— the witness lied—must be true. Choice A is incorrect because it asserts the witness told the truth, which directly conflicts with the established truth of the report and violates the logical inference.

The statement establishes membership as a necessary condition for attendance, meaning anyone attending must be a member. Since Sara is attending, she must be a member, making Option A the correct deduction. Option B is incorrect because it is too weak; we can conclude with certainty that Sara is a member, not just that she might be.

Since studying guarantees passing, but passing does not guarantee studying, we cannot certainly determine whether Maya studied. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.

• !Option A is a common trap that commits the formal logic fallacy of affirming the consequent by assuming passing requires studying.
• !Option B is incorrect because it is too weak; we can conclude with certainty that Sara is a member, not just that she might be.
• !Option A is incorrect because it directly contradicts the premise that all animals in the zoo are safe.
• !The premises state that either the witness lied or the report is wrong, and then affirm that the report is correct; by disjunctive syllogism the remaining alternative— the witness lied—must be true.

Answer each from memory — you'll see instantly whether you're right and why.

Run a focused 10-question mini-mock on Inference and see it stick.