Mathematics · Quantitative Aptitude

Number Operations and Properties

974 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 calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

Translate the following sentence into an algebraic equation: "13 diminished from twice a number is equal to 17"

  1. $2x-13=17$
  2. $13-2x=17$
  3. $2x-17=13$
  4. $2x+13=17$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let  the  number  be  $x.$


Twice  of  the  number  is  $2x$  and  $13$  is  diminished  from  $2x$  means  $(2x-13)$  and  it  is  equal   to   $17. $
 So  answer  is  option  A

Multiple choice maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

The equation for the statement:"half a number added to 10 is 15".

  1. $\dfrac{X}{2}\,+ 10\,+ 5$
  2. $\dfrac{X}{2}\,+ 10\,= 5$
  3. $\dfrac{X}{2}\,+ 15\,= 10$
  4. $\dfrac{X}{2}\,= -10\,+ 15$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the number be $X.$

Half of the number is $\dfrac{X}{2}$
Half a number added to $10$ is $\dfrac{X}{2}+10$
So, according to the question,
$\Rightarrow$  $\dfrac{X}{2}+10=15$

$\Rightarrow$  $\dfrac{X}{2}=-10+15$

Multiple choice maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

The equation for the statement; 'Half of a number added to $10$ is $15$' is __________.

  1. $\dfrac {x}{2} = 10 + 5$
  2. $\dfrac {x}{2} + 10 = 15$
  3. $\dfrac {x}{2} = 15 + 10$
  4. $\dfrac {x}{2} = 10 + 15$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let, the number be $x$
Half of a number $=$ $\dfrac{x}{2}$
Therefore, the required equation is $\dfrac{x}{2}$ $+10 = 15$.

Multiple choice maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

If a number, when divided by $4$, is reduced by $21$, the number is:

  1. $18$
  2. $20$
  3. $28$
  4. $38$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Let $x$ be the number.
If a number is divided by the $4$ the expression becomes $\dfrac{x}{4}$
If a number, when divided by $4$, is reduced by $21$, then the equation is
$\dfrac{x}{4}=x-21$
$\Rightarrow\,\dfrac{x}{4}-x=-21$
$\Rightarrow\,\dfrac{x-4x}{4}=-21$
$\Rightarrow\,-3x=-21\times 4$
$\Rightarrow\,x=\dfrac{21}{3}\times 4=7\times 4=28$
$\therefore\,$,the number is $28$
Multiple choice maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

The product of two numbers is 1296. If one number is 16 times the other, then the two numbers are 

  1. 144, 25

  2. 81, 49

  3. 144, 9

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the first number be $x$. Then, other number is $16x$.


Now, $x \times 16x =1296$

$16x^2=1296$
$x^2=81$
$x=9$
$16x=16\times 9=144$

Thus, the two numbers are $9$ and $144.$

Multiple choice maths calculations and mental strategies 1 equations from statements forming equations from statements writing mathematical statements

A boy was asked to multiply a certain number by $25$. He multiplied it by $52$ and got his answer more than the correct one by $324$. The number to be multiplied was:

  1. $12$
  2. $15$
  3. $25$
  4. $52$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Suppose  the number to be multiplied $= x$
As per Question
$\Rightarrow 52\times x = 25\times x + 324$
$ \Rightarrow 52x = 25x + 324$
$\Rightarrow  52x - 25x = 324$
$\Rightarrow 27x = 324$
$ x = 12 $
Hence, option 'A' is correct.

Multiple choice maths ways to multiply and divide mental multiplication multiplication methods multiplication of numbers

Product of $7,986$ and $548$ is

  1. $1,35,562$
  2. $43,76,328$
  3. $1,35,862$
  4. $1,35,462$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Unit digits of both numbers are $6$ and $8$. 

On multiplying the unit digits we get,
$6\times 8=48$
So, the unit digit of the product will be $8$.
There is only one option whose unit digit is $8$ i.e. option B.
So, correct answer is opiton B.