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
D
Correct answer
Explanation
Dividing by 1/2 is the same as multiplying by 2. So, 30 divided by 0.5 equals 60. Adding 10 to 60 results in 70. Common errors include dividing by 2 (getting 15) or misinterpreting the fraction.
B
Correct answer
Explanation
To find trailing zeros, count factors of 10 = min(factors of 2, factors of 5). Factor each number: 175 has 5², 180 has 2²·5, 12 has 2², 44 has 2², 80 has 2⁴·5, 66 has 2. Total twos = 11, total fives = 4. Min(11,4) = 4 trailing zeros.
C
Correct answer
Explanation
Use Legendre's formula: exponent of prime p in n! = floor(n/p) + floor(n/p²) + floor(n/p³) + ... For 150! and p=2: floor(150/2)=75, floor(150/4)=37, floor(150/8)=18, floor(150/16)=9, floor(150/32)=4, floor(150/64)=2, floor(150/128)=1. Sum = 146.
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5
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10
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20
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55
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cant be determined
E
Correct answer
Explanation
The sum of 10 consecutive numbers starting from x is 10x + 45 (since 0+1+...+9 = 45). The sum of 11 consecutive numbers starting from y is 11y + 55 (since 0+1+...+10 = 55). Setting them equal gives 10x + 45 = 11y + 55, which simplifies to 10x - 11y = 10. This is one equation with two variables, so x - y cannot be uniquely determined - it depends on the specific values chosen.
D
Correct answer
Explanation
Dividing by half is the same as multiplying by 2. 40 / 0.5 = 80. Then, 80 + 10 = 90. A common mistake is to divide by 2 (40/2=20), which would lead to 30.
C
Correct answer
Explanation
Following the order of operations, 5 divided by 1/2 is equivalent to 5 multiplied by 2, which equals 10. Adding 3 to 10 results in 13. Distractors like 5.5 or 12 result from incorrect arithmetic or ignoring the reciprocal rule.
D
Correct answer
Explanation
This is a logic puzzle. You can only subtract 6 from 30 once, because after you subtract it, you are subtracting from 24, then 18, and so on. The question asks how many times you can subtract it from 30 specifically.
C
Correct answer
Explanation
This is a visual riddle. If you 'subtract' (remove) the top half of the digit '8', you are left with a '0' (or two zeros). Mathematically, subtracting half of 8 (4) leaves 4, but the riddle relies on the shape of the numeral.
A
Correct answer
Explanation
To solve this problem, the user needs to know basic arithmetic and how to find the sum of two numbers. The user must check whether any two numbers in the given list add up to thirteen.
Let's go through each option:
A. True: This option is correct. By checking the given numbers, we can see that 2 of them add up to 13. 6 and 7 add up to 13. Thus, option A is the correct answer.
B. False: This option is incorrect. There are actually two numbers in the given list that add up to 13.
Therefore, the answer is:
The Answer is: A
B
Correct answer
Explanation
Dividing 30 by 1/2 equals 30 x 2 = 60. Adding 10 gives 70. Option A (25) mistakenly calculates 30 ÷ 2, while options C and D are other incorrect results. Remember: dividing by a fraction means multiplying by its reciprocal.
B
Correct answer
Explanation
Half means 0.5, so 30 divided by 0.5 = 30 × 2 = 60. Then 60 + 10 = 70. The common mistake is dividing by 2 instead of dividing by 0.5. 25 would come from 30 ÷ 2 + 10. 40 would come from 30 ÷ 0.5 × 2/3 roughly. 12 is unclear but wrong.
D
Correct answer
Explanation
Let the number be x. One-third of one-fourth of x equals 15: (1/3) × (1/4) × x = 15, which simplifies to x/12 = 15. Solving gives x = 180. Three-tenth of this number = (3/10) × 180 = 54.
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2197
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go to calculator and calculate..
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sooroor
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13*13*13
A
Correct answer
Explanation
Adding sequentially: 1000+40=1040, +1000=2040, +30=2070, +1000=3070, +20=3090, +1000=4090, +10=4100. The pattern is 4000 + (40+30+20+10) = 4100. This tests attention to detail in mental arithmetic.
C
Correct answer
Explanation
The mod function returns the remainder of division. -15 ÷ 4 = -3 with remainder -3, since -3 × 4 = -12 and -15 - (-12) = -3. Different languages handle negative operands differently, but -15 and 4 would typically give remainder -3 or 1 depending on implementation.