Little Learnersplay. practice. discover.Grade 12 · Reading & language
Use the exact direction of a stated rule to distinguish a guarantee from a requirement, without reversing an implication.
8 authored questions + worked example
The rule says: If a badge has a blue triangle, it opens this gate. No rule about other badges is supplied.
Answer: It is sufficient for opening; the text does not establish that it is necessary.
The rule guarantees opening for a blue-triangle badge but does not exclude other opening badges.
All 8 authored questions for this skill.
Question 1
In this invented system, every complete form is approved. A specific form was not approved. Treat the rule as exceptionless.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: That form was not complete.
If it were complete, the rule would require approval. Nonapproval therefore rules out completeness.
Question 2
A model says a signal is accepted exactly when tests A and B both succeed. A succeeds but B fails.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: The signal is not accepted.
Exactly when defines the joint requirement; one success does not satisfy both tests.
Question 3
The rule says: If a badge has a blue triangle, it opens this gate. No rule about other badges is supplied.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: It is sufficient for opening; the text does not establish that it is necessary.
The rule guarantees opening for a blue-triangle badge but does not exclude other opening badges.
Question 4
The notice says: A visitor is admitted only if the visitor has a ticket. It gives no promise that every ticket holder will be admitted.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: It is necessary, but admission is not guaranteed by it alone.
Only if makes the ticket a requirement; the notice does not make it a complete guarantee.
Question 5
This scoring protocol says a result is labelled pass if and only if its score is at least 80.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: It is both necessary and sufficient in this protocol.
If and only if supplies both directions: the score qualifies, and passing requires that score.
Question 6
An idealized rule states: Every sample containing marker X reacts. A particular sample does not contain marker X. Nothing is said about other causes of reaction.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: The rule alone does not determine whether this sample reacts.
The rule gives a sufficient condition, not an exclusive cause; lacking it does not settle the result.
Question 7
Assume this rule always holds: If the indicator is lit, the circuit is enabled. A check establishes that the circuit is not enabled.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: The indicator is not lit.
A lit indicator would imply enabled; the established not-enabled result rules out a lit indicator.
Question 8
The protocol says a trial may proceed only if both reviewers approve. Both reviewers have approved, but no other permission rule is stated.
If A then B guarantees B when A holds; B only if A makes A required. Do not silently turn either rule into an equivalence.
Answer: The stated requirement is met, but that sentence alone does not guarantee permission.
Both approvals satisfy a necessary condition. The text does not say it is sufficient.