Analogy (numbers) — “13 : 19 :: 21 : ?”. Complete the pair using the same +6 step (next number = previous + 6).
Verbal Reasoning
Analogy
Difficulty: Easy
Choose an option
Answer
Correct Answer: 27
Explanation
Introduction / Context:The pair 13 : 19 advances by +6 (13 + 6 = 19). Apply the same constant-difference rule to 21 to find the missing number.
Given Data / Assumptions:
- Rule: x → x + 6.
- We keep arithmetic in integers.
Concept / Approach:Compute 21 + 6.
Step-by-Step Solution:
Calculate: 21 + 6 = 27.Verification / Alternative check:Constant-difference analogies are common; no contradictory evidence exists in the stem.
Why Other Options Are Wrong:They do not equal 21 + 6.
Common Pitfalls:Overcomplicating with primes or products when a simple linear step fits the first pair exactly.
Final Answer:27