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SSC CGL Reasoning · Syllogism

Two-Statement Syllogism

Two statements about groups (All, Some, No) and two conclusions to test: a conclusion follows only if it must be true whenever both statements are true.

All Syllogism notes

Why this matters

Nineteen questions in the bank, all from the 2025 shifts, and all but one EASY. The whole chapter rests on a short table of rules for turning a statement round and for joining two statements, and this page teaches that table.

Concept 1 of 2: Turning a statement round and joining two

Draw each group as a circle. "All A are B" puts circle A inside circle B; "Some A are B" makes them overlap. A conclusion follows only if every drawing that fits the statements also fits the conclusion. A few rules save drawing every time.

Definition

  • Turning round (the converse): "All A are B" gives "Some B are A", never "All B are A". "Some A are B" gives "Some B are A".
  • Joining through the middle group B:
  • All A are B, and All B are C, give All A are C (and so Some C are A).
  • Some A are B, and All B are C, give Some A are C.
  • All A are B, and Some B are C, give nothing definite about A and C.
  • Some A are B, and Some B are C, give nothing definite about A and C.
  • Ignore what you know about the real world: the statements are the only facts.
  • Fast route: test each conclusion against the rules one at a time, and pick the option that names exactly the ones that pass.

Worked example

Statements: All cups are mugs. All mugs are jars. Conclusions: I. All cups are jars. II. Some jars are mugs. Which conclusions follow?
Practice this conceptself-check · 4 quick reps

The same idea in a real exam question:

SSC CGL · 2025 · Tier I, 23 Sep 2025, Shift 2 · Q12Easy

Example 1 · Syllogism · Two-Statement Syllogism

Read the following statement carefully and identify the conclusion that follows. Statement: Some humans are artists. All artists are creators. Conclusions: I. Some humans are creators. II. All creators are artists.

Turning "All" round into "All"

All dogs are animals, but not all animals are dogs. "All A are B" turned round gives only "Some B are A".

Joining two Some statements

Some boys are players and some players are singers does not tell you that any boy sings: the players who sing may be other players. Two Some statements give no definite link.
Drill 12 more on turning a statement round and joining two

Concept 2 of 2: Statements with No and Some not

"No A is B" draws the two circles apart. Joined with an All or a Some statement, it tells you which things are kept out of a group, and the conclusion that follows is often a "Some ... are not" statement.

Definition

  • Turning round: "No A is B" gives "No B is A". "Some A are not B" cannot be turned round.
  • Joining:
  • All A are B, and No B is C, give No A is C.
  • Some A are B, and No B is C, give Some A are not C.
  • No A is B, and All B are C, give Some C are not A (the Bs are Cs that are not A).
  • No A is B, and No B is C, give nothing definite about A and C.
  • A conclusion that says the opposite of a statement never follows.
  • Fast route: a "Some ... are not" conclusion usually comes from a Some or All statement joined to a No statement; check that pair first.

Worked example

Statements: No apple is a stone. All stones are rocks. Conclusions: I. Some rocks are not apples. II. No apple is a rock. Which conclusions follow?
Practice this conceptself-check · 4 quick reps

The same idea in a real exam question:

SSC CGL · 2025 · Tier I, 26 Sep 2025, Shift 3 · Q13Easy

Example 2 · Syllogism · Two-Statement Syllogism

Read the following statement carefully and identify the conclusion that follows. Statement: Some stars are planets. No planet is a comet. Conclusions: I. Some stars are not comets. II. All comets are planets.

Reading "Some A are not B" into "Some A are B"

"Some students are runners" does not mean some students are not runners: all of them might be. A "Some ... are not" conclusion needs a No statement behind it.

Joining two No statements

No cat is a dog and no dog is a fish say nothing about cats and fish. Two negative statements give no conclusion.
Drill 5 more on statements with no and some not

Summary — formulas & gotchas at a glance

A revision cheat-sheet for the formulas and gotchas above. Click any concept name to jump back to its full explanation.

Watch out for (4)

Test yourself on Syllogism

20 past SSC CGL questions from this chapter, timed at 12 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.

Take the Syllogism chapter testDrill all 19 questions