Home › CBSE Class 11 › mathematics › Sets — Definitions, Roster vs Set-Builder, Empty/Finite/Infinite/Equal Sets, Subsets › The set A = {x : x is a positive integer and x² …
The set A = {x : x is a positive integer and x² < 40} in roster form is:
A{0, 1, 2, 3, 4, 5, 6}
B{1, 2, 3, 4, 5, 6, 7}
C{1, 2, 3, 4, 5, 6}
D{1, 2, 3, 4, 5}
Answer & Solution
Correct answer: C. {1, 2, 3, 4, 5, 6}
Positive integers x with x² < 40: 1, 4, 9, 16, 25, 36 — all < 40; 7² = 49 > 40. So x ∈ {1, 2, 3, 4, 5, 6}. Note x is a POSITIVE integer so 0 is excluded.
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 collection is NOT a well-defined set?Which 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?