Syllogism

JKSSB Junior Engineer (Mechanical) · Reasoning · 19 practice questions with answers and explanations: 10 Easy, 9 Medium, 0 Hard.

Sample questions

Sample Easy question 1

Statements: All squares are polygons. All polygons are shapes. Conclusion I: All squares are shapes. Conclusion II: All shapes are squares. Which follows?

  1. Only I
  2. Only II
  3. Both I and II
  4. Neither
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Answer: A. Conclusion I follows the logical chain directly; Conclusion II reverses it and does not follow.

Sample Easy question 2

Statements: All squares are rectangles. Some rectangles are circles. Conclusion: Some squares are circles.

  1. Follows
  2. Does not follow
  3. Cannot be determined
  4. Both follow
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Answer: B. The rectangles that are circles aren't guaranteed to be the same ones that are squares, so the conclusion does not follow.

Sample Easy question 3

Statements: All cats are animals. All animals are living beings. Conclusion: All cats are living beings. Is this conclusion valid?

  1. Valid
  2. Invalid
  3. Cannot be determined
  4. None of these
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Answer: A. This is a valid syllogistic chain: cats ⊂ animals ⊂ living beings.

Sample Medium question 4

Statements: Some books are pens. All pens are pencils. Conclusion: Some books are pencils. Is this valid?

  1. Valid
  2. Invalid
  3. Cannot be determined
  4. None of these
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Answer: A. The books that are pens must also be pencils, since all pens are pencils.

Sample Medium question 5

Statements: All pens are objects. All objects have mass. Conclusion: All pens have mass. Is this valid?

  1. Valid
  2. Invalid
  3. Cannot be determined
  4. None of these
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Answer: A. Since pens are objects and all objects have mass, all pens must have mass.

Sample Medium question 6

Statements: No mangoes are vegetables. Some fruits are mangoes. Conclusion: Some fruits are not vegetables. Is this valid?

  1. Valid
  2. Invalid
  3. Cannot be determined
  4. None of these
Show answer

Answer: A. The fruits that are mangoes cannot be vegetables, so some fruits are indeed not vegetables.

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