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 equations and simple functions further equations solving linear equations with variable on both sides solution of linear equations in one variable

A boy was asked to multiply a given number by $\displaystyle \frac{8}{17}$. Instead, he divided the given number by $\displaystyle \frac{8}{17}$ and got the result $225$ more than what he should have got if he had multiplied the number by $\displaystyle \frac{8}{17}$. The given number was

  1. $8$
  2. $17$
  3. $64$
  4. $136$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the given number be $x$


According to problem, 

$ 225 + x(\cfrac {8}{17}) = \cfrac{x \times 17}{8}$
$ 225 = \cfrac{17x}{8} - \cfrac{8x}{17}$
$ 225 = \cfrac {225x}{136}$
$ x=136$

Multiple choice maths equations and simple functions further equations solving linear equations with variable on both sides solution of linear equations in one variable

A number is multiplied by $2\displaystyle\frac{1}{3}$ times itself and then $61$ is subtracted from the product obtained. If the final result is $9200$, then the number is __________.

  1. $36$
  2. $63$
  3. $67$
  4. $37$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let the number is $x$

According to given question, we have
$ x\times \dfrac{7x}{3} -61 = 9200$

$\Rightarrow \dfrac{7x^2}{3}=9261$
$\Rightarrow x^2=9261\times  \dfrac{3}{7}$
$\Rightarrow x^2 =3969$
$\Rightarrow x=\sqrt{3969}$
$\Rightarrow x=63$

Multiple choice maths equations and simple functions further equations solving linear equations with variable on both sides solution of linear equations in one variable

A number is multiplied by half of itself and then $32$ is added to the product, if the final result is $130$, then find the original number.

  1. $4$
  2. $7$
  3. $5$
  4. $14$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the number be $x$

According to given question, we have
$x\times  \dfrac{x}{2} +32=130$

$\Rightarrow \dfrac{x^2}{2}=98$
$\Rightarrow x^2=196$
$\Rightarrow x=14$

Therefore, the number is $14$.

Multiple choice maths equations and simple functions further equations solving linear equations with variable on both sides solution of linear equations in one variable

The difference of two numbers is $72$ and the quotient obtained by dividing one by the other is $3$. Find the numbers.

  1. $36$ $and$ $108$
  2. $16$ $and$ $88$
  3. $63$ $and$ $135$
  4. $\text{none}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$Let\>the\>numbers\>be\>x\>and\>y,\>then\>x-y=72\\and\>(\frac{x}{y})=3\\or\>x\>=\>3y\\\therefore\>3y-y=72\\2y=72\\\therefore\>y=36,\>then\>x\>=\>108$

Multiple choice maths vedic mathematics square roots using vedic maths square and square roots using vedic mathematics history of mathematics

When multiplied by itself, which number is equal to $12,345, 678, 987, 654, 321$?

  1. $1,111,111$
  2. $111,111,111$
  3. $11,111,111,111$
  4. $111,111,111,111$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
$(1)^2=1$
$(11)^2=121$
$(111)^2=12321$
$(111, 111, 111)^2=12345678987654321$
Here we can show a pattern for each count of $1$ in $LHS$ is extended the number from $1$ to that Number and reverse that number to the $1$ in $RHS$
Multiple choice maths length, mass and capacity problems on measurement choosing and converting between units conversion between different units

Convert the following into quintal:
$400\ $ ton

  1. $400$ quintal
  2. $4,000$ quintal
  3. $40$ quintal
  4. $4$ quintal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We know that


$1$  $ton =10$  $quintal$

$1$  $quintal =\dfrac1{10}$  $ton$

Given That, we have to convert $400$  $ton$  to   $quintals$

$400$  $tons =400 \times 10$  $quintals$

                   
                   $=4,000$  $quintals$

So, option $B$ is correct

Multiple choice maths length, mass and capacity problems on measurement choosing and converting between units conversion between different units

Convert the following into tons :
$670$ quintal

  1. $6700$ tons
  2. $670$ tons
  3. $67$ tons
  4. $6.7$ tons
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

We know that


$1$  $ton =10$  $quintal$

$1$  $quintal =\dfrac1{10}$  $ton$

Given That, we have to convert $670$  $quintal$  to   $tons$

$670$  $quintals =\dfrac{1}{10} \times 670$  $tons$

                    $ =\dfrac{670}{10} $  $tons$

                   $=67$  $tons$

So, option $C$ is correct

Multiple choice maths ratio, proportion and unitary method more on proportion terms related to proportion proportion

Mark the correct alternative of the following.
If $343$ is the third proportional of $a$ and $b,$ where $a : b=1 : 7$, then the values of $a+b$ is?

  1. $14$
  2. $24$
  3. $56$
  4. $63$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$a : b = b : 343$


$\dfrac{a}{b} = \dfrac{b}{343}$


$\dfrac{1}{7} = \dfrac{b}{343}$

$b = \dfrac{343}{7}$

$b = 49$

$\dfrac{a}{b} = \dfrac{1}{7}$

$\dfrac{a}{49} = \dfrac{1}{7}$

$a = \dfrac{49}{7} = 7$

$a + b = 49 + 7 = 56$