Home › CBSE Class 11 › mathematics › Sets — Definitions, Roster vs Set-Builder, Empty/Finite/Infinite/Equal Sets, Subsets › Which collection is NOT a well-defined set?
Which collection is NOT a well-defined set?
ACollection of ten most talented writers of India
BCollection of all natural numbers less than 100
CCollection of all months beginning with letter J
DCollection of all even integers
Answer & Solution
Correct answer: A. Collection of ten most talented writers of India
'Ten most talented writers' depends on subjective judgment — not well-defined. The other three have unambiguous membership criteria (January/June/July; even integers; naturals < 100).
Related questions
For A = {1, 2, 3}, identify which is a PROPER subset of A.A = {1, 3, 5} and B = {x : x is an odd natural number less than 6}. What is the relationshWhich statement about the EMPTY SET ∅ is INCORRECT?Let A = {n ∈ ℤ : n² ≤ 4} and B = {x ∈ ℝ : x² − 3x + 2 = 0}. Are A and B equal?Set X = letters in 'ALLOY'; set B = letters in 'LOYAL'. Compare:For the equation x² + x − 2 = 0, the solution set in roster form is:Which set is FINITE?Sets B = {x : x > 15 and x < 5}, C = {x : x − 5 = 0}, E = {x : x is an integral positive r