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Each of the following consists of a question and two statements, numbered (1) and (2). You must decide whether the data provided in the statements are sufficient to answer the question.

Question: What is the value of the positive integer n?

(1) The least common multiple (LCM) of n and 12 is 60.

(2) The greatest common divisor (GCD) of n and 12 is 1.

(A) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

(B) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

(C) BOTH statements (1) and (2) TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

(D) EACH statement ALONE is sufficient.

Correct Answer: (C)

1. Analysis of Statement (1): The LCM of $n$ and $12$ is $60$. Prime factorization of $12 = 2^2 \times 3^1$ and $60 = 2^2 \times 3^1 \times 5^1$. For the LCM to be $60$, $n$ must be a factor of $60$ and must contribute the factor $5^1$ which is missing in $12$. Possible values for $n$ include $5, 10, 15, 20, 30, 60$. Since there are multiple values, (1) alone is not sufficient.

2. Analysis of Statement (2): The GCD of $n$ and $12$ is $1$. This means $n$ is coprime to $12$, implying $n$ is not divisible by $2$ or $3$. There are infinitely many positive integers that satisfy this (e.g., $1, 5, 7, 11, \dots$). Thus, (2) alone is not sufficient.

3. Combining Both Statements: From (1), $n \in \{5, 10, 15, 20, 30, 60\}$. From (2), $n$ cannot be divisible by $2$ or $3$. Let us check the candidates: $5$ (not divisible by 2 or 3 - OK), $10$ (divisible by 2 - NO), $15$ (divisible by 3 - NO), $20$ (divisible by 2 - NO), $30$ (divisible by 2 and 3 - NO), $60$ (divisible by 2 and 3 - NO).

4. Conclusion: Only $n = 5$ satisfies both conditions. Therefore, the statements together provide a unique value.

Test Prep Tip: When dealing with LCM and GCD, always use prime factorization. Remember that $LCM(a, b) \times GCD(a, b) = a \times b$. In Data Sufficiency, once you narrow down to a single possible value using both statements, you have achieved sufficiency.