Statements and Assumptions

• What an "assumption" means in verbal reasoning, and how it differs from a fact, an inference, or a conclusion.
• A reliable test to check whether an assumption is truly implicit in a given statement.
• How to avoid common traps where an option looks reasonable but is not necessarily assumed.

1. Assumption: Something that is taken for granted, not explicitly stated in the statement, but which the statement depends on to make sense. The speaker (or writer) believes it to be true without saying so.
2. The "necessity" test: An assumption is implicit only if the statement would not make sense, or the action described would not be logical, without that assumption being true. Ask: "If this assumption were false, would the statement still be sensible?" If the answer is no, the assumption is implicit.
3. Not the same as a general fact: A statement about a widely known truth (e.g., "electricity is costly") is not automatically an implicit assumption of a specific statement unless that specific statement actually depends on it.
4. Not the same as a prediction or an opinion: An assumption about what will happen next (e.g., "everyone will follow this rule") is usually too strong to be a necessary assumption — the statement can be true even if that prediction turns out wrong.
5. Beware of extreme words: Options using words like "all," "always," "never," or "only" are frequently traps — real assumptions are usually more modest and specific to what the statement needs.
6. Two-assumption format: Most exam questions give a Statement followed by two Assumptions (I and II). You must judge each independently before combining your answer into one of: Only I, Only II, Both, or Neither.

Statement: "The library has introduced a new rule: books must be returned within 14 days, or a fine will be charged."

I. Some borrowers do not return books within 14 days on their own. II. A fine will stop all borrowers from ever returning books late again.

Apply the necessity test to each:

I: If NO borrower ever kept a book beyond 14 days, would this rule be needed? No — so I is implicit.
II: Is it necessary that the fine stops ALL late returns forever for the rule to make sense? No — the rule can
    exist and be reasonable even if it only reduces late returns partially. II is too strong, so it is NOT implicit.

Answer: Only I is implicit.

• Picking an option because it is plausible or commonly true, rather than because the statement needs it to be true.
• Confusing an assumption with the purpose or result the speaker hopes for (a hope is not a necessary assumption).
• Automatically choosing "Both" or "Neither" without testing each assumption separately using the necessity test.
• Missing that extreme, absolute wording ("all," "never," "definitely") almost always signals a non-implicit, trap assumption.

• A shop puts up a sign: "50% off, today only." What must the shopkeeper be assuming for this sign to make sense as a marketing move?
• A school circular says, "Late-comers will not be allowed to enter after the first period." What does this circular assume about student behaviour?

Open the Practice tab for graded questions on Statements and Assumptions.