Difficulty: Medium
Correct Answer: None of these
Explanation:
Introduction / Context:We must decide which statements allow us to identify a unique two-digit number. Represent the number as 10a + b with digits a (tens) and b (units).
Given Data / Assumptions:
Concept / Approach:Combine conditions and see if a unique (a, b) pair emerges. With |a − b| = 3 and 1 ≤ a ≤ 9, 0 ≤ b ≤ 9, many numbers satisfy the constraints.
Step-by-Step Solution:
From I: |a − b| = 3.From II: |a − b| = 3 (duplicate of I).From III: b = a − 3, which is one orientation of the absolute difference.Numbers satisfying III include 41, 52, 63, 74, 85, 96 (all valid two-digit numbers).Even with all three, multiple solutions exist; hence no unique number can be determined.Verification / Alternative check:Test any candidate from the set; each meets I, II, III and yields the same 27 difference from its reverse. Non-uniqueness persists.
Why Other Options Are Wrong:
Common Pitfalls:Assuming the difference with reverse fixes the number; it fixes only the digit gap.
Final Answer:None of these
Discussion & Comments