UPSC Prelims 2025·CSAT·Quantitative Aptitude·Number System

A question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct option. What is the smallest 1-digit number having exactly 4 distinct factors ? Statement I : 2 is one of the factors. Statement II : 3 is one of the factors. Which one of the following is correct in respect of the above Question and the Statements ?

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Last updated 23 May 2026, 3:31 pm IST
  1. AThe Question can be answered by using one of the Statements alone, but cannot be answered using the other statement alone.
  2. BThe Question can be answered by using either Statement alone.
  3. CThe Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
  4. DThe Question can be answered even without using any of the Statements.Correct

Explanation

The question asks for the smallest 1-digit number having exactly 4 distinct factors. Let's find this number by checking 1-digit numbers: - 1 has 1 factor (1) - 2 has 2 factors (1, 2) - 3 has 2 factors (1, 3) - 4 has 3 factors (1, 2, 4) - 5 has 2 factors (1, 5) - 6 has 4 factors (1, 2, 3, 6) - 7 has 2 factors (1, 7) - 8 has 4 factors (1, 2, 4, 8) - 9 has 3 factors (1, 3, 9) The 1-digit numbers with exactly 4 distinct factors are 6 and 8. The smallest among these is 6. Therefore, the answer to the question "What is the smallest 1-digit number having exactly 4 distinct factors?" is 6. We were able to determine this answer (6) by directly analyzing the 1-digit numbers and their factors, without using any information from Statement I or Statement II. Let's briefly analyze the statements, though not strictly necessary for option D: Statement I: 2 is one of the factors. - If the number is 6, 2 is a factor. - If the number is 8, 2 is a factor. This statement alone would not uniquely identify 6 as the smallest, as both 6 and 8 satisfy having 2 as a factor and 4 distinct factors. Statement II: 3 is one of the factors. - If the number is 6, 3 is a factor. - If the number is 8, 3 is NOT a factor. This statement alone would uniquely identify 6 as the answer among the candidates (6 and 8). However, the core point is that the original question can be solved independently. Option D states: The Question can be answered even without using any of the Statements. As shown above, we found the answer to be 6 by direct calculation, without needing Statement I or Statement II. Hence, option D is correct. The final answer is D.
Quantitative Aptitude: A question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct o

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