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

Multiple choice maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

The two numbers formed by subtracting one from $5$ and $10$ are:

  1. 11 and 12

  2. 4 and 10

  3. 4 and 9

  4. 5 and 6
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let us first subtract one from $5$ as shown below:


$5-1=4$ 

Similarly, subtract one from $10$ as follows:

$10-1=9$ 

Hence, the two numbers formed by subtracting one from $5$ and $10$ are $4$ and $9$.

Multiple choice maths average arithmetic mean of ap introduction to averages means

What is the arithmetic mean of the progression $11, 22, 33, 44, 55, 66, 77?$

  1. $44$
  2. $208$
  3. $308$
  4. $48$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using the formula for required arithmetic mean $=\dfrac{\text{sum of the terms}}{\text{number of terms}}$


After substituing the values we get: $=\dfrac{11+22+33+44+55+66+77}{7}$

                                                $\quad \quad \quad =\dfrac{11(1+2+3+4+5+6+7)}{5}=\dfrac{11\cdot 28}{7}=11\cdot 4=44$

Multiple choice maths average arithmetic mean of ap introduction to averages means

Find  AM  of  first $250$  natural numbers.

  1. $115$
  2. $225$
  3. $125$
  4. $125.5$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sum of first 250 natural numbers:

$S=\dfrac{n(n+1)}{2}=\dfrac{250\times 251}{2}$
$\therefore A.M.=\dfrac{S}{n}=\dfrac{250\times 251}{250\times 2}=125.5$

Multiple choice maths average arithmetic mean of ap introduction to averages means

If $a,b,c,d,e,f$ are $A.M.s$ between $2$ and $12$ then $a+b+c+d+e+f$ is equal to

  1. $14$
  2. $42$
  3. $84$
  4. $None\ of\ these$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When n arithmetic means are inserted between two numbers p and q, their sum is equal to n times the single arithmetic mean of the two numbers, or n * (p + q) / 2. Here there are 6 means between 2 and 12, so the sum is 6 * (2 + 12) / 2 = 6 * 7 = 42.

Multiple choice maths average arithmetic mean of ap introduction to averages means

$11\,AM's$ are inserted between $28$ and $10$ then ${6}^{th}\,AM$ is 

  1. $19$
  2. $\displaystyle 17\frac{1}{2}$
  3. $\displaystyle 20\frac{1}{2}$
  4. $22$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Common difference d = (10 - 28) / (11 + 1) = -18 / 12 = -1.5. The 6th A.M. is a + 6d = 28 + 6(-1.5) = 28 - 9 = 19.

Multiple choice maths multiplication and division of integers division of integers and its properties multiplying and dividing integers multiplication of integers

Divide:
$(-60 \times -72)  \  by\    (36\times (-15))$

  1. -8

  2. -16

  3. 8

  4. 16
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Given, $

\dfrac { (-60)\times (-72) }{ 36\times (-15) } $

As there are $ 2 $ negative numbers in the numerator and $ 1 $ in the

denominator, the answer will be negative.

Cancelling out the common factors and simplifying we get

$ \dfrac { (-60)\times (-72) }{ 36\times (-15) }=-4\times 2  = - 8 $