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Siblings — How many sisters does K have? Statements: I. M is a sister of K. II. K’s mother has three children.

Difficulty: Medium

Statement I alone is sufficient; Statement II alone is not sufficient.
Either Statement I alone or Statement II alone is sufficient.
Either Statement I alone or Statement II alone is sufficient.
Both Statements I and II together are not sufficient to answer the question.
Both Statements I and II together are sufficient, but neither alone is sufficient.

Correct Answer: Both Statements I and II together are not sufficient to answer the question.

Explanation:

Introduction / Context:
We need the exact count of K's sisters from family-size and one-known-sister facts.

Given Data / Assumptions:

I: K has at least one sister (M).
II: Total children of K’s mother = 3 (includes K).

Concept / Approach:
Enumerate possibilities for the third child’s gender.

Step-by-Step Solution:

From I alone: #sisters ≥ 1, but could be 1 or 2; insufficient.From II alone: With 3 children total, the composition is unknown; #sisters for K could be 0, 1, or 2; insufficient.Together: We know one sister (M) and one additional sibling whose gender is unknown. Therefore, #sisters ∈ {1,2}. Not unique.

Verification / Alternative check:
Case A: (K male), siblings = {M (F), X (M)} → 1 sister. Case B: (K male), siblings = {M (F), X (F)} → 2 sisters. Both obey I & II.

Why Other Options Are Wrong:

A/B/C/E: Neither statement alone suffices; even together they do not fix a unique number.

Common Pitfalls:
Assuming genders not stated; presuming K’s own gender.

Final Answer:
D — Together not sufficient.

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Siblings — How many sisters does K have? Statements: I. M is a sister of K. II. K’s mother has three children.

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