Tag: operations on rational numbers

Questions Related to operations on rational numbers

Which of the following rational numbers lies between $0$ and $-1$?

  1. $0$

  2. $-1$

  3. $\dfrac {-1}{4}$

  4. $\dfrac {1}{4}$


Correct Option: C
Explanation:

Clearly, $0$ and $-1$ cannot lie between $0$ and $-1$. 

Also, 
$0=\dfrac{0}{4}$ and $-1=\dfrac{-4}{4}$
We can clearly see that $\dfrac {-1}{4}$ lies between $0$ and $-1$.

If we divide a positive integer by another positive integer, what is the resulting number?

  1. It is always a natural number

  2. It is always an integer

  3. It is a rational number

  4. It is an irrational number


Correct Option: C
Explanation:

When a positive integer is divided by another positive integer will yield a rational number

The rational number lying exactly in between the numbers $\displaystyle \frac { 1 }{ 5 } $ and $\displaystyle \frac { 1 }{ 3 } $ is

  1. $\displaystyle \frac { 1 }{ 2 } $

  2. $\displaystyle \frac { 1 }{ 4 } $

  3. $\displaystyle \frac { 2 }{ 15 } $

  4. $\displaystyle \frac { 4 }{ 15 } $

  5. $\displaystyle \frac { 8 }{ 15 } $


Correct Option: D
Explanation:

Required number $=$ $\dfrac{1}{2}\left(\dfrac{1}{5}+\dfrac{1}{3}\right)$

$\Rightarrow \dfrac{1}{2}\left(\dfrac{3+5}{15}\right)$
$\Rightarrow \dfrac{1}{2}\times \dfrac{8}{15}=\dfrac{4}{15}$
Hence, $\dfrac{4}{15}$ is a rational number lying between $\dfrac{1}{5}$ and $\dfrac{1}{3}$.

Identify a rational number between $\dfrac {1}{3}$ and $\dfrac {4}{5}$

  1. $\dfrac {1}{4}$

  2. $\dfrac {9}{10}$

  3. $\dfrac {17}{30}$

  4. $\dfrac {7}{10}$


Correct Option: C,D
Explanation:

Converting the given fraction in decimal format we get $\frac { 1 }{ 3 } =0.33\quad and\quad \frac { 4 }{ 5 } =0.8$

Now converting all option in decimal we get
A.  $\frac{1}{4}$=0.25
B. $\frac{9}{10}$=0.9
C. $\frac{17}{30}$=0.567
D.  $\frac{7}{10}$ =0.7
So it is clear that option C and D lies between 0.33 and 0.8 and both are rational numbers so correct answer will be option C and D

State true or false:

Five rational numbers between.
$\dfrac{2}{3}$ and $\dfrac{4}{5}$ are $\dfrac{41}{60},\dfrac{42}{60},\dfrac{43}{60},\dfrac{44}{60},\dfrac{45}{60}$
  1. True

  2. False


Correct Option: A
Explanation:

To get the rational numbers between $\displaystyle\frac{2}{3}$ and $\displaystyle\frac{4}{5}$

Take an LCM of these two numbers: $\displaystyle\frac{10}{15}$ and $\displaystyle\frac{12}{15}$

Multiply numerator and denominator by 4: $\displaystyle\frac{40}{60}$ and $\displaystyle\frac{48}{60}$

All the numbers between $\displaystyle\frac{40}{60}$ and $\displaystyle\frac{48}{60}$ form the answer

Some of these numbers are $\displaystyle\frac{41}{60}$, $\displaystyle\frac{42}{60}$, $\displaystyle\frac{43}{60}$, $\displaystyle\frac{44}{60}$, $\displaystyle\frac{45}{60}$


Hence the statement is true

Three rational numbers between $\frac{2}{5}$ and $\frac{3}{5}$ is  $\frac{9}{20},\frac{10}{20},\frac{11}{20}$
If true then enter $1$ and if false then enter $0$

  1. True

  2. False


Correct Option: A

The rational number between $\displaystyle \frac{1}{3}$ and $\displaystyle \frac{1}{2}$ is _________.

  1. $\displaystyle \frac{2}{5}$

  2. $\displaystyle \frac{1}{5}$

  3. $\displaystyle \frac{3}{5}$

  4. $\displaystyle \frac{4}{5}$


Correct Option: A
Explanation:

$\dfrac{1}{3} = 0.3333.....$


$\dfrac{1}{2} = 0.5$

Option A :
$\dfrac{2}{5} = 0.4$

Option B :
$\dfrac{1}{5} = 0.2$

Option C :
$\dfrac{3}{5} = 0.6$

Option D :
$\dfrac{4}{5} = 0.8$

$\therefore$ Option A lies in between $\dfrac{1}{3}$ and $\dfrac{1}{2}$

Choose the rational number, which does not lie, between the rational numbers, $\frac{-2}{3}$ and $\frac{-1}{5}$

  1. $\frac{-3}{10}$

  2. $\frac{3}{10}$

  3. $\frac{-1}{4}$

  4. $\frac{-7}{20}$


Correct Option: B
Explanation:

Both given rational numbers are negative rational number. So, a rational number between both these rational numbers will be negative. But option B is a positive. So, option B will not lie between the given rational numbers. So, correct answer is option B.

State true or false:

Five rational numbers between.
$\dfrac{1}{4}$ and $\dfrac{1}{2}$ are $\displaystyle\frac{9}{32},\frac{10}{32},\frac{11}{32},\frac{12}{32},\frac{13}{32}$
  1. True

  2. False


Correct Option: A
Explanation:

To get the rational numbers between $\displaystyle\frac{1}{4}$ and $\displaystyle\frac{1}{2}$

Take an LCM of these two numbers: $\displaystyle\frac{1}{4}$ and $\displaystyle\frac{2}{4}$

Multiply numerator and denominator by 8: $\displaystyle\frac{8}{32}$ and $\displaystyle\frac{16}{32}$

All the numbers between $\displaystyle\frac{8}{32}$ and $\displaystyle\frac{16}{32}$ form the answer

Some of these numbers are $\displaystyle\frac{9}{32}$, $\displaystyle\frac{10}{32}$, $\displaystyle\frac{11}{32}$, $\displaystyle\frac{12}{32}$, $\displaystyle\frac{13}{32}$

State true or false:

Five rational numbers between.
$\dfrac{-3}{2}$ and $\dfrac{5}{3}$ are $\dfrac{-8}{6},\dfrac{-7}{6},0,\dfrac{1}{6},\dfrac{2}{6}$
  1. True

  2. False


Correct Option: A
Explanation:

To get the rational numbers between $\displaystyle\frac{-3}{2}$ and $\displaystyle\frac{5}{3}$

Take an LCM of these two numbers: $\displaystyle\frac{-9}{6}$ and $\displaystyle\frac{10}{6}$

All the numbers between $\displaystyle\frac{-9}{6}$ and $\displaystyle\frac{10}{6}$ form the answer

Some of these numbers are $\displaystyle\frac{-8}{6}$, $\displaystyle\frac{-7}{6}$, $\displaystyle{0}$, $\displaystyle\frac{1}{6}$, $\displaystyle\frac{2}{6}$


Hence the statement is true