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 hcf-lcm introduction to multiples multiples lcm

Find the first four common multiples of the following :

$3, 4$ and $6$.

  1. $72, 78, 84, 90$
  2. $12, 24, 36, 48$
  3. $24, 30, 36, 42$
  4. $8, 12, 16, 21$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiples of $ 3 = 3, 6, 9, 12, 15, 18.. $
Multiples of $ 4 = 4, 8, 12, 16, 20.. $

Multiples of $ 6 = 6, 12, 18, 36.. $ 


The first common multiple will be $ 12 $

And the next common multiples will be multiples of $ 12 $

Hence, first four common multiples of $ 3, 4, 6 $ are $ 12, 24, 36, 48 $

Multiple choice maths hcf-lcm introduction to multiples multiples lcm

Find the first four common multiples of the following :

$8$ and $12$.

  1. $24, 48, 72, 96$
  2. $24, 36, 48, 56$
  3. $24, 32, 40, 48$
  4. $48, 72, 96, 120$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Multiples of $ 8 = 8, 16, 24, 32, .. $
Multiples of $ 12 = 12, 24, 36, 48... $

The first common multiple will be $ 24 $

And the next common multiples will be multiples of $ 24 $

Hence, first four common multiples of $ 8, 12 $ are $ 24, 48, 72, 96  $

Multiple choice maths hcf-lcm introduction to multiples multiples lcm

Find the first six multiples of $17$

  1. $17, 51, 85, 102, 119$
  2. $34, 76, 102, 119, 340$
  3. $34, 51, 68, 102, 170$
  4. $17, 34, 51, 68, 85, 102$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

First six multiples of $ 17 =  17, 34, 51, 68, 85$ and $102. $

Multiple choice maths hcf-lcm introduction to multiples multiples lcm

Find a number which has a multiple of all the numbers from $1$ to $10?$

  1. $5040$
  2. $1260$
  3. $720$
  4. $1440$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Number which has a multiple of all the numbers from 1 to 10 will be multiple of their LCM.

$LCM (1,2,3,4,5,6,7,8,9,10)= 2520$
The only multiple of 2520 from the options is 5040 which is option A so correct answer will be option A

Multiple choice maths hcf-lcm introduction to multiples multiples lcm

Find a possible value of $v$, if the least common multiple of $9, 10, 12$ and $v$ is $540$.

  1. 18

  2. 24

  3. 27

  4. 36

  5. 45
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

LCM of 9,10,12

$9=3\times 3$
$10=2\times 5$
$12=2\times 2\times 3$
$LCM(9,10,12)=2\times 2\times 3\times 3\times 5=180$
180 is also multiply of 18,36,45.If v is 18,36 and 45 than LCM of all the number would be 180 but its 540 so the answer is Option C.

Multiple choice business economics and quantitative methods measures of dispersion and skewness shortcut method for calculating mean deviation about mean mean deviation about mean and median range and mean deviation

The A.M of two numbers is $6.5$ and their G.M is $6$. The two numbers are _____.

  1. $8, 6$
  2. $8, 5$
  3. $7, 16$
  4. $4, 9$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Given AM = (a+b)/2 = 6.5, so a+b = 13. Given GM = sqrt(ab) = 6, so ab = 36. The numbers 4 and 9 satisfy a+b = 13 and ab = 36.

Multiple choice maths direct proportion and inverse proportion inverse proportion rule of three types of proportions
 $x$ $ 2$  $4$ $ 20$  $15$
 $y$  $3$  $7$ $ 10$  $12$
 $z$  $10$ $ 5$ $ 1$  $4/3$

Observe the table and find the quantities which are in inverse proportion

  1. $x \ and \ y$
  2. $x \ and \ z$
  3. $y \ and \ z$

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

By definition of inverse proportion,

$a \  \alpha \  \dfrac{1}{b}$ i.e. $a = K \dfrac{1}{b}$                $K=$ constant of proportionality
$\therefore a\times b = K$  
From given example, consider
$x \times y =2\times 3 \neq 4\times 7 \neq 20\times 10\neq 15\times 12$
$x\times z = 2\times 10 = 4\times 5 = 20\times 1 = 15\times \dfrac{4}{3} = 20$
$\therefore$ $x$ and $z$ obey the equation $1$
Hence $x$ and $z$ are in inverse proportion.
Answer is B

Multiple choice maths hcf-lcm introduction to multiples multiples lcm

What are the three common multiples of $18$ and $6$?

  1. $18, 6, 9$
  2. $18,36,6$
  3. $36, 54, 72$

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

Multiples of $ 18 = 18, 36, 54, 72..... $

Multiples of $ 6 = 6, 12, 18, 24.... $
The first common multiple will be $ 18 $

And the next common multiples will be multiples of $ 18 $
Hence, the common multiples of $ 18, 6 $ are $ 18, 36, 54, 72 $...

Multiple choice maths concepts of seven and eight digit numbers comparison of numbers comparing numbers operations on rational numbers indian place value chart largest and smallest numbers writing and expanding numbers

Arrange in descending order:
$6,00,780;  5,56,879; 6,87,340; 4,76,980$

  1. $4,76,980; 6,00,780; 5,56,879; 6,87,340; $
  2. $5,56,879;6,00,780; 6,87,340; 4,76,980$
  3. $ 6,87,340; 6,00,780;5,56,879; 4,76,980$
  4. $6,00,780; 6,87,340; 4,76,980; 5,56,879;$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Comparing digits at lakh's place followed by ten thousand's, thousand's, hundred's, ten's and one's place,


We can arrange the given numbers in descending order as 
$6,87,340;\ 6,00,780;\ 5,56,879;\ 4,76,980$

Multiple choice maths concepts of seven and eight digit numbers comparison of numbers comparing numbers operations on rational numbers indian place value chart largest and smallest numbers writing and expanding numbers

Arrange in ascending order:
$12,098; 12,908; 12,809; 12,890$

  1. $12,098; 12,908; 12,809; 12,890$
  2. $12,098;12,809; 12,890; 12,908;$
  3. $12,098;12,890; 12,908; 12,809$
  4. $12,890; 12,908; 12,809; 12,098$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Comparing digits at ten thousand's place followed by thousand's, hundred's, ten's and one's place,


We can arrange the given numbers in ascending order as 
$12,098; 12,809; 12,890; 12,908$