Logical equivalence (conditional meaning): interpret the sentence that begins with "Unless" Original sentence: "Unless you work harder, you will fail." Choose the option that correctly paraphrases the meaning without changing the sense of the condition.

Given data

• Target sentence: "Unless you work harder, you will fail."
• Task: Find a logically equivalent paraphrase.

Concept/Approach
In conditional logic, unless P, Q is equivalent to if not P, then Q. Here, P = "you work harder" and Q = "you will fail". So the accurate restatement is: "If you do not work harder, you will fail."

Option analysis
(a) Introduces "plan well" and changes the condition — incorrect.(b) Reverses cause and effect — incorrect.(c) Adds an alien idea "work alone" — incorrect.(d) If you do not put more effort, then you will fail — matches the logical form of "unless". ✅

Common pitfalls

• Reading "unless" as "if and only if" — it is not biconditional.
• Adding new conditions that are not in the original sentence.

Final Answer
If you do not put more effort, then you will fail.