LNAT Logical Deduction 2 — Questions and Answers
Question 1: All judges are lawyers. Some lawyers are professors. Which conclusion must be true?
- All judges are professors
- Some judges are professors
- No judges are professors
- Some lawyers are judges (Correct answer)
Correct answer: Some lawyers are judges
Since all judges are lawyers, it follows necessarily that some lawyers (namely, all judges) are judges.
Question 2: If the defendant is acquitted, the prosecution will appeal. The prosecution did not appeal. What can we conclude?
- The defendant was convicted (Correct answer)
- The prosecution was satisfied
- The defendant was acquitted
- The appeal was denied
Correct answer: The defendant was convicted
By modus tollens: if acquittal leads to appeal, and there was no appeal, then there was no acquittal — meaning the defendant was convicted.
Question 3: In a group of 50 students, 30 study philosophy and 25 study history. What is the minimum number who study both?
- 0
- 5 (Correct answer)
- 10
- 25
Correct answer: 5
The minimum overlap is 30 + 25 − 50 = 5, by the inclusion-exclusion principle.
Question 4: Every contract requires offer, acceptance, and consideration. This agreement has offer and acceptance but no consideration. What follows?
- It is a valid contract
- It is not a valid contract (Correct answer)
- It may be a valid contract
- Consideration can be implied
Correct answer: It is not a valid contract
Since a necessary condition (consideration) is absent, the agreement cannot be a valid contract.
Question 5: Only barristers can appear in the Supreme Court. Sarah appeared in the Supreme Court. Therefore:
- Sarah is a solicitor
- Sarah is a barrister (Correct answer)
- Sarah studied law
- Sarah won her case
Correct answer: Sarah is a barrister
'Only barristers can appear' means appearing implies being a barrister, so Sarah must be a barrister.
Question 6: If A testifies, B will be implicated. If B is implicated, C will resign. A testifies. What must follow?
- B testifies
- C resigns (Correct answer)
- A is acquitted
- B resigns
Correct answer: C resigns
By chained modus ponens: A testifies → B implicated → C resigns.
Question 7: No criminal acts are morally praiseworthy. Some courageous acts are criminal. Which statement is supported?
- All courageous acts are morally praiseworthy
- Some courageous acts are not morally praiseworthy (Correct answer)
- No courageous acts are morally praiseworthy
- Morally praiseworthy acts are never courageous
Correct answer: Some courageous acts are not morally praiseworthy
The courageous acts that are criminal cannot be morally praiseworthy, so some courageous acts are not morally praiseworthy.
LNAT Logical Deduction 2
All judges are lawyers.
Some lawyers are professors.
Which conclusion must be true?