Lessons / Logical reasoning
Logical reasoning · Day 10

Statements: Assumptions and Conclusions

An assumption is something the speaker must take for granted; a conclusion is something that must follow from the statement. Neither may add outside facts.

Practise (3 questions) Present as slides

Why this topic matters

'Buy our soap for glowing skin.' The advertiser assumes people want glowing skin. An assumption is what the speaker must believe for the statement to make sense.

These questions test careful reading, not maths. The rules are strict: an assumption is unstated and necessary; a conclusion follows from the statement alone.

Assumptions

An assumption is something the speaker takes for granted without saying it. Test: if the assumption were false, would the statement still make sense? If not, it is assumed.

Reject anything that is merely possible, or too extreme ('only', 'always', 'all').

Example 1Statement: 'Please send your CV by email.' Assumption I: the reader has access to email. Assumption II: CVs sent by post will be rejected.
  1. If the reader had no email, the request would make no sense, so I is assumed.Negation test.
  2. Nothing says post is rejected; II goes beyond the statement.
  3. Only I is implicit.

Conclusions

A conclusion must follow from the statement alone, without outside knowledge. Stay inside the facts given.

Watch definite words: 'all', 'never', 'must'. A conclusion using them needs statement support for them.

Example 1Statement: 'Most students of this college got placed this year.' Conclusion I: some students were not placed. Conclusion II: the college has good teachers.
  1. 'Most' means not all, so some were not placed.I follows from the words.
  2. Nothing is said about teachers.II needs outside knowledge.
  3. Only I follows.

Formula summary

Assumption test
If the assumption were false, would the statement still make sense? If not, it is implicit.
Conclusion test
Must be true for ANY reader who accepts the statement. 'May', 'always', 'only' usually break it.
Advertisement statements
Assume people read ads and the product is worth buying.
Extreme words
'Only', 'all', 'never', 'best' in an option usually make it wrong.

Shortcuts and tricks

Negation test

Use it when: Deciding if an assumption is implicit.

  1. Negate it and re-read the statement.
Example'Use Brand X soap for soft skin.' Assumption: people want soft skin.
  1. If nobody wanted soft skin the ad is pointless.
  2. So it is implicit.

Before you move on, you should be able to...

  • test an assumption by negating it
  • accept only conclusions that use the statement's facts
  • reject extreme words without support

Practice questions (3)

Try each one before opening the solution. Or practise them one by one so your score is saved.

easy Statement: 'Please book tickets in advance to avoid last-minute rush.' Assumption: there is usually a rush at the last minute.
  1. The advice only makes sense if a rush happens.

Answer: Implicit

easy Statement: 'All students who scored above 90% will get a scholarship. Ravi scored 92%.' Conclusion: Ravi will get a scholarship.
  1. Direct application of the rule.

Answer: Follows

medium Statement: 'The government has increased the fee for driving licences.' Conclusion: fewer people will now drive.
  1. A fee change does not force driving behaviour.

Answer: Does not follow

Class plan (2 hours, for trainers)

A tested order for teaching this topic in one 2-hour session. Present mode follows the same order.

10 minWarm-up.
30 minAssumptions with the negation test.
30 minConclusions: inside the facts.
45 minPractice set with discussion.
5 minRecap.
← Seating ArrangementPuzzles →
Statements: Assumptions and ConclusionsPractise now