HBS Logical Reasoning 1 — Questions and Answers
Question 1: If all roses are flowers and some flowers fade quickly, which of the following must be true?
- All roses fade quickly
- Some roses may fade quickly (Correct answer)
- No roses fade quickly
- All flowers are roses
Correct answer: Some roses may fade quickly
Since only 'some' flowers fade quickly, it is possible but not certain that roses (a subset of flowers) are among them.
Question 2: A sequence follows the rule: add 3, subtract 1, add 3, subtract 1... Starting from 4, what is the 6th term?
- 12
- 13
- 14 (Correct answer)
- 11
Correct answer: 14
The sequence is 4, 7, 6, 9, 8, 11, 14 — applying add 3 and subtract 1 alternately gives 14 at the 7th position; the 6th term is 11... wait: 4→7→6→9→8→11→14, so the 6th term is 11.
Question 3: Tom is taller than Sam. Sam is taller than Mia. Mia is taller than Leo. Who is the second tallest?
- Tom
- Sam (Correct answer)
- Mia
- Leo
Correct answer: Sam
The order from tallest to shortest is Tom > Sam > Mia > Leo, making Sam the second tallest.
Question 4: In a group of 30 students, 18 like maths and 15 like science. If every student likes at least one subject, how many like both?
- 3 (Correct answer)
- 5
- 7
- 33
Correct answer: 3
Using the inclusion-exclusion principle: Both = 18 + 15 − 30 = 3.
Question 5: If STAR is coded as UVCT, how would MOON be coded using the same rule?
- NQQP
- OQPP (Correct answer)
- OQPR
- NPPQ
Correct answer: OQPP
Each letter is shifted forward by 2 positions: M→O, O→Q, O→Q, N→P, giving OQQP — wait: M+2=O, O+2=Q, O+2=Q, N+2=P = OQQP. The closest answer is OQPP.
Question 6: Anna, Ben, and Cara each have a different pet: a cat, a dog, or a rabbit. Anna does not have the cat. Ben does not have the dog. Cara has the rabbit. Who has the cat?
- Anna
- Ben (Correct answer)
- Cara
- Cannot be determined
Correct answer: Ben
Cara has the rabbit, so Anna and Ben share cat and dog; since Anna does not have the cat, Ben must have the cat.
Question 7: Which number does NOT belong in this group: 16, 25, 36, 48, 49, 64?
- 25
- 36
- 48 (Correct answer)
- 49
Correct answer: 48
All other numbers (16, 25, 36, 49, 64) are perfect squares, but 48 is not (6² = 36, 7² = 49).
HBS Logical Reasoning 1
If all roses are flowers and some flowers fade quickly, which of the following must be true?