Number System Questions and Answers – Page 4

For “Find the square of 25”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: 25² = 625.. The distractors 725, 825, 525 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value. An independent reverse-check again gives 625.

The verified answer is 126, option C. For “Which number is divisible by 3?”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: Sum = 9 divisible by 3.. The distractors 124, 125, 127 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value.

Use prime factorisation; HCF takes minimum powers and LCM takes maximum powers. For “Find the HCF of 24 and 36”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: HCF is 12.. Write one justified transformation per line, cancel common factors only when multiplication permits it, and preserve the left-to-right rule for operations of equal priority. Estimate the expected sign and approximate magnitude before accepting an option. The exact answer should be consistent with those bounds and with every restriction in the stem. This explanation connects the result with a reproducible method instead of isolated answer recall and strengthens calculation discipline, pattern recognition and option elimination for SSC, Railway, Banking and other competitive aptitude examinations.

Use prime factorisation; HCF takes minimum powers and LCM takes maximum powers. For “Find the LCM of 12 and 18”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: LCM of 12 and 18 is 36.. Write one justified transformation per line, cancel common factors only when multiplication permits it, and preserve the left-to-right rule for operations of equal priority. Estimate the expected sign and approximate magnitude before accepting an option. The exact answer should be consistent with those bounds and with every restriction in the stem. This explanation connects the result with a reproducible method instead of isolated answer recall and strengthens calculation discipline, pattern recognition and option elimination for SSC, Railway, Banking and other competitive aptitude examinations.

The verified answer is 121, option D. For “Which number is a perfect square?”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: 121 = 11².. The distractors 122, 123, 124 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value. An independent reverse-check again gives 121.

Translate the statement into integer, fraction or place-value relations and simplify systematically. For “Find the value of 999 × 9”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: 999×9 = 9000−9 = 8991.. The distractors 8999, 8990, 9000 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value.

The verified answer is 234, option B. For “Which number is divisible by 9?”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: Sum of digits of 234 is 9.. The distractors 238, 235, 236 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value.

For “What least number must be added to 789 so that it is divisible by 11?”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: 789 leaves remainder 10 so +1..

For “(125 × 48) = ?”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. The question-specific working recorded with the item is: 125×48 = 125×(50−2)=6250−250=6000.. The distractors 6500, 7000, 5000 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value. An independent reverse-check again gives 6000.

The verified answer is निम्नलिखित में से कितनी संख्याएँ 132 से विभाज्य हैं? For “How many of the following numbers are divisible by 132? 264”, retain the exact signs, brackets, powers and numerical conditions before beginning the calculation. Accuracy depends on separating the mathematical structure from the surface size of the numbers. The distractors 462, 968, 5184 may arise from changing the order of operations, mishandling a negative sign, using an incorrect reciprocal, ignoring a divisibility condition, or rounding an exact value.