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Class 11 | CBSE | MATHEMATICS
SETS | ASSERTION -REASON
ASSERTION – REASON Worksheet (Class 11 | CBSE)
Chapters: 1.6 Subsets · 1.6.1 Subsets of ℝ · 1.6.2 Intervals as subsets of ℝ · 1.7 Universal Set
Directions: For each question, choose the correct option:
(A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are true but Reason is not the correct explanation.
(C) Assertion is true but Reason is false.
(D) Assertion is false but Reason is true.
1.
Assertion (A): Every set is a subset of itself.
Reason (R): Every element of a set belongs to the same set.
2.
Assertion (A): The set of rational numbers is a subset of the set of real numbers.
Reason (R): Every rational number can be expressed as a real number.
3.
Assertion (A): The interval (2, 5] is a subset of ℝ.
Reason (R): An interval contains only real numbers between given limits.
4.
Assertion (A): The universal set depends on the context of the problem.
Reason (R): The universal set contains all elements under consideration.
5.
Assertion (A): The interval (3, 7) includes the numbers 3 and 7.
Reason (R): Open intervals exclude their end points.
6.
Assertion (A): If A ⊆ B, then A ⊆ ℝ when B ⊆ ℝ.
Reason (R): A subset of a subset of ℝ is also a subset of ℝ.
7.
Assertion (A): The empty set is a subset of every set.
Reason (R): The empty set has no elements that can violate the subset condition.
🧠 Neurological Insight (Assertion–Reason Mastery)
The brain evaluates Assertion–Reason questions in two passes:
① Truth check (Is each statement true?)
② Causal link check (Does R explain A?)
Fast Exam Strategy:
• If A is false → eliminate (A) & (B)
• If R explains “why” A is true → choose (A)
• Memorize: ⊆, ℝ, intervals, U as mental blocks, not sentences
🧠 This reduces cognitive load and speeds up decision-making under exam pressure.