Which set is FINITE?

Question

Accepted Answer

C. {x ∈ ℕ : (x − 1)(x − 2) = 0}

Option A = {1, 2} — finite.
Option B = ∅ (2x − 1 = 0 → x = 1/2, not a natural number); ∅ is finite too.
But the standard answer treats option A as the unambiguous finite NON-EMPTY set.
Option C (primes) and D (odd naturals) are infinite.
(Strictly both A and B are finite — typical syllabus exercise emphasises A as 'finite' since B = ∅ counts as 'empty/finite'; in the choice list above A is the unambiguous answer for 'finite non-empty'.)

Answer

{x ∈ ℕ : x is odd}

Answer

{x ∈ ℕ : 2x − 1 = 0}

Answer

{x ∈ ℕ : x is prime}

Which set is FINITE?

Keep practising Unit 1A3: Function Composition and Inverses