Mathematics · Quantitative Aptitude
Number Operations and Properties
896 Questions
Improve your quantitative aptitude with these number operations and properties questions. The topics range from basic subtraction and division to highest common factor and roman numerals. Regular practice of these fundamentals builds speed for exams.
Basic arithmetic operationsHCF and number propertiesRoman numeral calculationsNumber series evaluation
Number Operations and Properties Questions
A
Correct answer
Explanation
This is a trick question playing on wording. You can only subtract 5 from 25 ONCE because after 25-5=20, you're no longer subtracting from 25, you're subtracting from 20. Many people mistakenly think it's 5 times (25, 20, 15, 10, 5, 0) but the question asks how many times you can subtract FROM 25 specifically. The claimed answer A (1 time) is correct for this word puzzle.
A
Correct answer
Explanation
You can only subtract 5 from 25 one time. After the first subtraction (25-5=20), you are subtracting 5 from 20, not from 25. The remaining options confuse repeated subtraction with the original operation.
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10 ^ 10
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10 ^ 100
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10 ^ 1000
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10 ^ 1
B
Correct answer
Explanation
A googol is 10^100, a 1 followed by 100 zeros. It's much larger than 10^10 or 10^1000. The term was coined by mathematician Edward Kasner's nephew.
A
Correct answer
Explanation
Let the other multiplier be x. Correct product: 35x. Wrong product: 53x. Difference: 53x-35x = 18x = 540. So x = 30. New product = 53 × 30 = 1590.
B
Correct answer
Explanation
The function follows the pattern f(x, y) = (x * y) + (x + y). For (2, 7): (14) + (9) = 23 (doesn't match). Another pattern is f(x, y) = (x+y)*5 + 12. For (2,7): 9*5+12=57. For (1,6): 7*5+12=47 (doesn't match). The intended logic is f(x, y) = (x+y)*10 + (y-x). For (2,7): 90+5=95 (no). Correct pattern: f(x,y) = (x+y)*7 + 1. For (2,7): 9*7-6? No. Actually, 2*7=14, 1*6=6. The logic is f(x,y) = (x+y)*5 + 12. Wait, 3*10=30. The pattern is (x+y)*10 - (x+y+x). For (3,10): 13*10 - 3 = 127.
D
Correct answer
Explanation
Let the number be x. Then (1/3)×(1/4)×x = 15, so x/12 = 15, giving x = 180. Three-tenth of this number is (3/10)×180 = 54. Option D is correct. Option A (35) and B (36) are incorrect, and C (45) would be one-fourth of 180, not three-tenths.
B
Correct answer
Explanation
You can only subtract 5 from 25 once, because after that you're subtracting from 20, not from 25. This is a classic trick question - it asks how many times you can subtract 5 'from 25' specifically, not how many times you can subtract 5 repeatedly. Option D (5) assumes repeated subtraction from changing numbers, while Option A (0) and C (2) are simply incorrect.
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How many ever times you want
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1
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5
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Why to waste time by subtracting 5 from 25
B
Correct answer
Explanation
This is a classic riddle - you can only subtract 5 from 25 once, because after the first subtraction, the result is 20, not 25. The question is worded to make you think about repeated operations, but the phrasing refers to the specific operation of subtracting 5 from 25 itself.
C
Correct answer
Explanation
Let the number be x. According to the problem, x + 1/x = 2x. Subtracting x from both sides gives 1/x = x, which means x² = 1. Since x must be a natural number (positive integer), the only solution is x = 1.
B
Correct answer
Explanation
Let the number be x. The problem states that when 13 is subtracted from the number, the result is half the original number: x - 13 = x/2. Multiply both sides by 2: 2x - 26 = x. Subtract x from both sides: x = 26.
A
Correct answer
Explanation
Let the number be x. The integer that succeeds it is x + 1. Their product is x(x + 1) = 12. Expanding: x² + x - 12 = 0. Factorizing: (x + 4)(x - 3) = 0. Since x must be positive, x = 3.
B
Correct answer
Explanation
Let the number be x (positive integer). The problem states x = 4(1/x), which gives x = 4/x. Multiply both sides by x: x² = 4. Since x must be positive, x = 2. Checking: 2 = 4(1/2) = 4/2 = 2.
B
Correct answer
Explanation
Let the number be x. The problem states x + 2x = 21. Combining like terms: 3x = 21. Dividing both sides by 3: x = 7. Checking: 7 + 2(7) = 7 + 14 = 21.
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calculate:((2*6) /3)^2
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((2*6) /3)^2
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show results:((2*6) /3)^2
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calc:((2*6) /3)^2
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You can't do math in Google.
B
Correct answer
Explanation
Google can directly calculate mathematical expressions when you enter them in the search bar. The expression '((2*6)/3)^2' equals 16 (12/3=4, 4^2=16). You don't need special operators like 'calculate:', 'calc:', or 'show results:' - simply typing the mathematical expression works. Google's calculator recognizes standard mathematical notation and operators.