NCERT · Class 10 · Mathematics · Real NumbersWhich of the following is a prime number?
Step-by-Step Solution
The correct answer is B (13).
Explanation:
- 15 is divisible by 1, 3, 5, and 15 (composite).
- 13 is divisible only by 1 and 13 (prime).
- 21 is divisible by 1, 3, 7, and 21 (composite).
- 27 is divisible by 1, 3, 9, and 27 (composite).\nTherefore, 13 is a prime number.
Detailed Options Breakdown
Option : 15
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Real Numbers.
Option 1: 13 (Correct Answer)
Correct choice. Refer to the step-by-step verified solution guidelines above for details.
Option 2: 21
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Real Numbers.
Option 3: 27
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Real Numbers.
💡 Study Guide: This question tests core syllabus concepts from Real Numbers. For formulas, key summaries, and mock exam reference guides, read the full Real Numbers Revision Notes.