IDAT Logical Reasoning 2 — Questions and Answers
Question 1: All doctors are scientists. Some scientists are professors. Which conclusion must be true?
- All doctors are professors
- Some doctors are professors
- Some scientists are doctors (Correct answer)
- No doctors are professors
Correct answer: Some scientists are doctors
Since all doctors are scientists, doctors form a subset of scientists, so some scientists must be doctors.
Question 2: A sequence follows this rule: each term is the sum of the two preceding terms. If the sequence starts 3, 5, 8, 13 ... what is the next term?
- 18
- 19
- 21 (Correct answer)
- 26
Correct answer: 21
13 + 8 = 21, following the rule that each term equals the sum of the two before it.
Question 3: If no hawks are doves, and all doves are birds, which statement is definitely false?
- Some birds are hawks
- All hawks are birds
- Some doves are hawks (Correct answer)
- No birds are doves
Correct answer: Some doves are hawks
Since no hawks are doves, it is impossible for any doves to be hawks — this contradicts the given premise.
Question 4: A store offers a 20% discount, then an additional 10% off the discounted price. What is the total percentage reduction from the original price?
- 28% (Correct answer)
- 30%
- 25%
- 32%
Correct answer: 28%
20% off gives 80% of original; 10% off that gives 72%, so the total reduction is 28%.
Question 5: In a class of 30 students, 18 play soccer and 14 play basketball. If 6 students play neither sport, how many play both?
- 6
- 8 (Correct answer)
- 10
- 12
Correct answer: 8
Students in at least one sport = 30 − 6 = 24; using inclusion-exclusion: 18 + 14 − x = 24, so x = 8.
Question 6: Which word does NOT belong with the others: Simile, Metaphor, Alliteration, Hypothesis?
- Simile
- Metaphor
- Alliteration
- Hypothesis (Correct answer)
Correct answer: Hypothesis
Simile, metaphor, and alliteration are all literary/rhetorical devices; hypothesis is a scientific term.
Question 7: If A > B, B > C, and C > D, which of the following must be true?
- A > D (Correct answer)
- D > A
- B > D only if A > C
- A = D
Correct answer: A > D
By transitivity: A > B > C > D, so A must be greater than D.
IDAT Logical Reasoning 2
All doctors are scientists.
Some scientists are professors.
Which conclusion must be true?