Part CCSIR NET June 2025balanced-and-orthogonal-are-different-properties-and-a-bibd-has-only-the-first

Balanced and orthogonal are different properties and a bibd has only the first

If the incidence matrix of a block design is given by N with rows (1, 1, 1, 0), (1, 1, 0, 1), (1, 0, 1, 1) and (0, 1, 1, 1), then which of the following statements are true?

A.The design is incomplete✓
B.The design is connected✓
C.The design is balanced✓
D.The design is orthogonal

You have the answer. Trap Analysis is why the other three were written.

Not a worked solution repeated four times — the specific reasoning error each wrong option was built to reward, and why this one tests invariants don't determine.

See pricing

50 are analysed free — try those first.

The trap it tests

Invariants don't determine

Two objects sharing an invariant were treated as the same object.

Drill statements like this

Balanced and orthogonal are different properties and a bibd has only the first

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