HAST Logical Reasoning 1 — Questions and Answers
Question 1: All mammals are warm-blooded. All dogs are mammals. What conclusion must be true?
- Some dogs are warm-blooded
- All dogs are warm-blooded (Correct answer)
- All warm-blooded animals are dogs
- No dogs are warm-blooded
Correct answer: All dogs are warm-blooded
This is a valid syllogism: if all mammals are warm-blooded and all dogs are mammals, then all dogs must be warm-blooded.
Question 2: If it rains, the ground gets wet. The ground is not wet. What can you conclude?
- It is raining
- It did not rain (Correct answer)
- It might have rained
- The ground is dry because of wind
Correct answer: It did not rain
This uses modus tollens: if the consequence (wet ground) is false, the cause (rain) must also be false.
Question 3: No reptiles are warm-blooded. A lizard is a reptile. Which statement is valid?
- A lizard is warm-blooded
- A lizard is not warm-blooded (Correct answer)
- Some lizards are warm-blooded
- Warm-blooded animals include lizards
Correct answer: A lizard is not warm-blooded
Since no reptiles are warm-blooded and a lizard is a reptile, the lizard cannot be warm-blooded.
Question 4: Only students who study pass the exam. Maria passed the exam. What must be true?
- Maria did not study
- Maria studied (Correct answer)
- Maria was lucky
- The exam was easy
Correct answer: Maria studied
If passing requires studying, and Maria passed, then Maria must have studied.
Question 5: In a sequence: every even number is followed by its half. Starting at 64, what is the fourth number?
- 4
- 8 (Correct answer)
- 16
- 32
Correct answer: 8
64 → 32 → 16 → 8: each step halves the value, so the fourth number is 8.
Question 6: Some athletes are students. All students study hard. Which conclusion is definitely valid?
- All athletes study hard
- Some athletes study hard (Correct answer)
- No athletes study hard
- All students are athletes
Correct answer: Some athletes study hard
Since some athletes are students and all students study hard, those athlete-students must study hard — so some athletes study hard.
Question 7: If a shape has four equal sides and four right angles, it is a square. Shape X has four equal sides but no right angles. What is Shape X?
- A square
- A rectangle
- A rhombus (Correct answer)
- A trapezoid
Correct answer: A rhombus
A rhombus has four equal sides but does not require right angles, fitting the description of Shape X.
HAST Logical Reasoning 1
All mammals are warm-blooded.
All dogs are mammals.
What conclusion must be true?