Tag: equivalent fractions

Questions Related to equivalent fractions

A student was asked to solve the fraction $\cfrac { \cfrac { 7 }{ 3 } +\left( 1\cfrac { 1 }{ 2 }  \times\cfrac { 5 }{ 3 } \right) }{ 2+1\cfrac { 2 }{ 3 }  } $ and his answer was $\cfrac{1}{4}$. By how much was his answer wrong?

  1. $1$

  2. $\cfrac{1}{55}$

  3. $\cfrac{1}{220}$

  4. None of these


Correct Option: D
Explanation:
$ \dfrac{\dfrac{7}{3}+(1\dfrac{1}{2}\times \dfrac{5}{3})}{2+1\dfrac{2}{3}}$

$ = \dfrac{\dfrac{7}{3}+(\dfrac{3}{2}\times \dfrac{5}{3})}{(2+\dfrac{5}{3})}$

$  = \dfrac{\dfrac{7}{3}+\dfrac{5}{2}}{\dfrac{11}{3}} = \dfrac{14+15}{6}\times \dfrac{3}{11} = \dfrac{29}{22}$

$ \Rightarrow $ His answer was wrong by

$ \dfrac{29}{22}-\dfrac{1}{4} = \dfrac{116-22}{88} = \dfrac{94}{88} = \dfrac{47}{44}$


Which of the following fraction is the smallest? $\dfrac{7}{6}, \dfrac{7}{9}, \dfrac{4}{5}, \dfrac{5}{7}$

  1. $\dfrac{7}{6}$

  2. $\dfrac{7}{9}$

  3. $\dfrac{4}{5}$

  4. $\dfrac{5}{7}$


Correct Option: D
Explanation:
let the fractions be a, b, c, d
$ \dfrac{a}{b} = \dfrac{7}{6}\times \dfrac{9}{7} = \dfrac{9}{6}> 1\Rightarrow a> b$
a is not smallest
$ \dfrac{b}{c} = \dfrac{7}{9}\times \dfrac{4}{5} = \dfrac{28}{45}< 1\Rightarrow c> b$
 c is not smallest
$ \dfrac{b}{d} = \dfrac{7}{9}\times \dfrac{7}{5} = \dfrac{49}{45}> 1\Rightarrow b> d$
$ \Rightarrow $ d  is smallest $\Rightarrow (D)$

Write the following as fractions in their simplest form.

  1. 0.4

  2. 1.5

  3. 25.75

  4. 0.072

  5. 1.248


Correct Option: A
Explanation:

$0.4=\dfrac 4{10}=\dfrac 25\1.5=\dfrac{15}{10}=\dfrac 32\25.75=\dfrac{2575}{100}=\dfrac{103}{4}\0.072=\dfrac{72}{1000}=\dfrac{9}{125}\1.248=\dfrac{1248}{1000}=\dfrac{156}{125}$

$\dfrac{2}{3}$ is equal to $\dfrac{4}{6}$.

  1. True

  2. False


Correct Option: A
Explanation:

Now,

$\dfrac{4}{6}$

$=\dfrac{2\times 2}{2\times 3}$

$=\dfrac{2}{3}$.

Hence the given statement is correct.

The fraction $\displaystyle \frac{3}{5}$ is found between which pair of fractions on a number line?

  1. $\displaystyle \frac{7}{10}$ and $\displaystyle \frac{3}{4}$

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

  3. $\displaystyle \frac{1}{3}$ and $\displaystyle \frac{5}{13}$

  4. $\displaystyle \frac{2}{7}$ and $\displaystyle \frac{8}{11}$


Correct Option: D
Explanation:

(a) Let us consider the first set of fraction $\dfrac { 7 }{ 10 } ,\dfrac { 3 }{ 4 }$ and another given fraction $\dfrac { 3 }{ 5 }$ 


Taking the LCM to make the denominators same of the above fractions, we have

$\dfrac { 7\times 2 }{ 10\times 2 } ,\dfrac { 3\times 4 }{ 5\times 4 } ,\dfrac { 3\times 5 }{ 4\times 5 } \\ =\dfrac { 14 }{ 20 } ,\dfrac { 12 }{ 20 } ,\dfrac { 15 }{ 20 } \\ \Rightarrow \dfrac { 12 }{ 20 } <\dfrac { 14 }{ 20 } <\dfrac { 15 }{ 20 } \\ \Rightarrow \dfrac { 3 }{ 5 } <\dfrac { 7 }{ 10 } <\dfrac { 3 }{ 4 }$   

Therefore, $\dfrac { 3 }{ 5 }$ does not lie between the first set of fraction $\dfrac { 7 }{ 10 } ,\dfrac { 3 }{ 4 }$.

(b) Now, consider the set of fraction $\dfrac { 2 }{ 5 } ,\dfrac { 1 }{ 2 }$ and another given fraction $\dfrac { 3 }{ 5 }$

Taking the LCM to make the denominators same of the above fractions, we have

$\dfrac { 2\times 2 }{ 5\times 2 } ,\dfrac { 3\times 2 }{ 5\times 2 } ,\dfrac { 1\times 5 }{ 2\times 5 } \\ =\dfrac { 4 }{ 10 } ,\dfrac { 6 }{ 10 } ,\dfrac { 5 }{ 10 } \\ \Rightarrow \dfrac { 4 }{ 10 } <\dfrac { 5 }{ 10 } <\dfrac { 6 }{ 10 } \\ \Rightarrow \dfrac { 2 }{ 5 } <\dfrac { 1 }{ 2 } <\dfrac { 3 }{ 5 }$     

Therefore, $\dfrac { 3 }{ 5 }$ does not lie between the set of fraction $\dfrac { 2 }{ 5 } ,\dfrac { 1 }{ 2 }$.

(c) Now, consider the set of fraction $\dfrac { 1 }{ 3 } ,\dfrac { 5 }{ 13 }$ and another given fraction $\dfrac { 3 }{ 5 }$


Taking the LCM to make the denominators same of the above fractions, we have

$\dfrac { 1\times 65 }{ 3\times 2 } ,\dfrac { 3\times 39 }{ 5\times 39 } ,\dfrac { 5\times 15 }{ 13\times 15 } \\ =\dfrac { 65 }{ 195 } ,\dfrac { 108 }{ 195 } ,\dfrac { 75 }{ 195 } \\ \Rightarrow \dfrac { 65 }{ 195 } <\dfrac { 75 }{ 195 } <\dfrac { 108 }{ 195 } \\ \Rightarrow \dfrac { 1 }{ 3 } <\dfrac { 5 }{ 13 } <\dfrac { 3 }{ 5 }$     

Therefore, $\dfrac { 3 }{ 5 }$ does not lie between the set of fraction $\dfrac { 1 }{ 3 } ,\dfrac { 5 }{ 13 }$.

(d) Now, consider the set of fraction $\dfrac { 2 }{ 7 } ,\dfrac { 8 }{ 11 }$ and another given fraction $\dfrac { 3 }{ 5 }$

Taking the LCM to make the denominators same of the above fractions, we have

$\dfrac { 2\times 55 }{ 7\times 55 } ,\dfrac { 3\times 77 }{ 5\times 77 } ,\dfrac { 8\times 35 }{ 11\times 35 } \\ =\dfrac { 110 }{ 385 } ,\dfrac { 221 }{ 385 } ,\dfrac { 280 }{ 385 } \\ \Rightarrow \dfrac { 110 }{ 385 } <\dfrac { 221 }{ 385 } <\dfrac { 280 }{ 385 } \\ \Rightarrow \dfrac { 2 }{ 7 } <\dfrac { 3 }{ 5 } <\dfrac { 8 }{ 11 }$     

Therefore, $\dfrac { 3 }{ 5 }$ lies between the set of fraction $\dfrac { 2 }{ 7 } ,\dfrac { 8 }{ 11 }$.

Hence, the fraction $\dfrac { 3 }{ 5 }$ is found between $\dfrac { 2 }{ 7 }$ and $\dfrac { 8 }{ 11 }$ on a number line.

Which one of the following sets of fractions is in the correct sequence of ascending order of their values ?

  1. $\displaystyle -\frac{1}{2},\frac{5}{6},\frac{-4}{9}$

  2. $\displaystyle -\frac{3}{7},\frac{-5}{6},\frac{3}{5}$

  3. $\displaystyle -\frac{1}{2},-\frac{4}{9},\frac{5}{6}$

  4. $\displaystyle -\frac{4}{9},\frac{5}{6},\frac{1}{6}$


Correct Option: C
Explanation:

(a) Let us consider the first set of fraction $-\dfrac { 1 }{ 2 } ,\dfrac { 5 }{ 6 } ,-\dfrac { 4 }{ 9 }$ 


Taking the LCM to make the denominators same of the above fractions, we have

$-\dfrac { 1\times 9 }{ 2\times 9 } ,\dfrac { 5\times 3 }{ 6\times 3 } ,-\dfrac { 4\times 2 }{ 9\times 2 } \\ =-\dfrac { 9 }{ 18 } ,\dfrac { 15 }{ 18 } ,-\dfrac { 8 }{ 18 } \\ \Rightarrow -\dfrac { 9 }{ 18 } <-\dfrac { 8 }{ 18 } <\dfrac { 15 }{ 18 } \\ \Rightarrow -\dfrac { 1 }{ 2 } <-\dfrac { 4 }{ 9 } <\dfrac { 5 }{ 6 }$   

Therefore, the first set of fraction $-\dfrac { 1 }{ 2 } ,\dfrac { 5 }{ 6 } ,-\dfrac { 4 }{ 9 }$ is not in ascending order.

(b) Now, consider the set of fraction $-\dfrac { 3 }{ 7 } ,-\dfrac { 5 }{ 6 } ,\dfrac { 3 }{ 5 }$ 

Taking the LCM to make the denominators same of the above fractions, we have

$-\dfrac { 3\times 30 }{ 7\times 30 } ,-\dfrac { 5\times 15 }{ 6\times 15 } ,\dfrac { 3\times 42 }{ 5\times 42 } \\ =-\dfrac { 90 }{ 210 } ,-\dfrac { 175 }{ 210 } ,\dfrac { 126 }{ 210 } \\ \Rightarrow -\dfrac { 175 }{ 210 } <-\dfrac { 90 }{ 210 } <\dfrac { 126 }{ 210 } \\ \Rightarrow -\dfrac { 5 }{ 6 } <-\dfrac { 3 }{ 7 } <\dfrac { 3 }{ 5 }$    

Therefore, the set of fraction $-\dfrac { 3 }{ 7 } ,-\dfrac { 5 }{ 6 } ,\dfrac { 3 }{ 5 }$ is not in ascending order.


(c) Now, consider the set of fraction $-\dfrac { 1 }{ 2 } ,-\dfrac { 4 }{ 9 } ,\dfrac { 5 }{ 6 }$ 


Taking the LCM to make the denominators same of the above fractions, we have

$-\dfrac { 1\times 9 }{ 2\times 9 } ,-\dfrac { 4\times 2 }{ 9\times 2 } ,\dfrac { 5\times 3 }{ 6\times 3 } \\ =-\dfrac { 9 }{ 18 } ,-\dfrac { 8 }{ 18 } ,\dfrac { 5 }{ 18 } \\ \Rightarrow -\dfrac { 9 }{ 18 } <-\dfrac { 8 }{ 18 } <\dfrac { 5 }{ 18 } \\ \Rightarrow -\dfrac { 1 }{ 2 } <-\dfrac { 4 }{ 9 } <\dfrac { 5 }{ 6 }$    

Therefore, the set of fraction $-\dfrac { 1 }{ 2 } ,-\dfrac { 4 }{ 9 } ,\dfrac { 5 }{ 6 }$ is in ascending order.

(d) Now, consider the set of fraction $-\dfrac { 4 }{ 9 } ,\dfrac { 5 }{ 6 } ,\dfrac { 1 }{ 6 }$ 

Taking the LCM to make the denominators same of the above fractions, we have

$-\dfrac { 4\times 2 }{ 9\times 2 } ,\dfrac { 5\times 3 }{ 6\times 3 } ,\dfrac { 1\times 3 }{ 6\times 3 } \\ =-\dfrac { 8 }{ 18 } ,\dfrac { 15 }{ 18 } ,\dfrac { 3 }{ 18 } \\ \Rightarrow -\dfrac { 8 }{ 18 } <\dfrac { 3 }{ 18 } <\dfrac { 15 }{ 18 } \\ \Rightarrow -\dfrac { 4 }{ 9 } <\dfrac { 1 }{ 6 } <\dfrac { 5 }{ 6 }$    

Therefore, the set of fraction $-\dfrac { 4 }{ 9 } ,\dfrac { 5 }{ 6 } ,\dfrac { 1 }{ 6 }$ is not in ascending order.

Hence, the only set of fraction in ascending order is $-\dfrac { 1 }{ 2 } ,-\dfrac { 4 }{ 9 } ,\dfrac { 5 }{ 6 }$

Which of the following statements is true ?

  1. $\displaystyle {\frac{5}{7}\, <\, \frac{7}{9}\, <\, \frac{9}{11}\, <\, \frac{11}{13}}$

  2. $\displaystyle {\frac{11}{13}\, <\, \frac{9}{11}\, <\, \frac{7}{9}\, <\, \frac{5}{7}}$

  3. $\displaystyle {\frac{5}{7}\, <\, \frac{11}{13}\, <\, \frac{7}{9}\, <\, \frac{9}{11}}$

  4. $\displaystyle {\frac{5}{7}\, <\, \frac{9}{11}\, <\, \frac{11}{13}\, <\, \frac{7}{9}}$


Correct Option: A
Explanation:
Here we have four factors $\dfrac{5}{7},  \dfrac{7}{9},   \dfrac{9}{11},   \dfrac{11}{13}$
LCM of 7, 9, 11 and 13 is 9009
So, 
$\dfrac{5}{7} \times\dfrac{1287}{1287}$ = $\dfrac{6435}{9009}$

$\dfrac{7}{9} \times\dfrac{1001}{1001}$ = $\dfrac{7007}{9009}$

$\dfrac{9}{11} \times\dfrac{819}{819}$ = $\dfrac{7371}{9009}$

$\dfrac{11}{13} \times\dfrac{693}{693}$ = $\dfrac{7623}{9009}$
As, 
6435 < 7007 < 7371 < 7623
So, $\dfrac{5}{7} < \dfrac{7}{9} <  \dfrac{9}{11} <  \dfrac{11}{13}$

Arrange the following numbers in descending order.
$-2,\, \displaystyle {\frac{4}{-5},\, \frac{-11}{20},\, \frac{3}{4}}$

  1. $\displaystyle {\frac{3}{4}\, >\, -2\, >\, \frac{-11}{20}\, >\, \frac{4}{-5}}$

  2. $\displaystyle {\frac{3}{4}\, >\, \frac{-11}{20}\, >\, \frac{4}{-5}\, >\, -2}$

  3. $\displaystyle {\frac{3}{4}\, >\, \frac{4}{-5}\, >\, -2\, >\, \frac{-11}{20}}$

  4. $\displaystyle {\frac{3}{4}\, >\, \frac{4}{-5}\, >\, \frac{-11}{20}\, >\, -2}$


Correct Option: B
Explanation:

The rational number $\dfrac {4}{-5}$ is same as $\dfrac {-4}{5}$.


Now consider the given rational numbers $-2,\dfrac {-11}{20},\dfrac {-4}{5}$ and $\dfrac {3}{4}$ and make their denominator same by taking the LCM of the denominators as follows:

LCM$(5,20,4)=20$

The given fractions now with denominator $20$ can be written as:

$\dfrac { -2\times 20 }{ 1\times 20 } =\dfrac { -40 }{ 20 } \ \dfrac { -4\times 4 }{ 5\times 4 } =\dfrac { -16 }{ 20 } \ \dfrac { -11\times 1 }{ 20\times 1 } =\dfrac { -11 }{ 20 } \ \dfrac { 3\times 5 }{ 4\times 5 } =\dfrac { 15 }{ 20 }$ 

The descending order of the rational numbers is:

$\dfrac { 15 }{ 20 } >\dfrac { -11 }{ 20 } >\dfrac { -16 }{ 20 } >\dfrac { -40 }{ 20 } \ \Rightarrow \dfrac { 3 }{ 4 } >\dfrac { -11 }{ 20 } >\dfrac { 4 }{ -5 } >-2$ 

Hence, the descending order is $\dfrac { 3 }{ 4 } >\dfrac { -11 }{ 20 } >\dfrac { 4 }{ -5 } >-2$.

The average of the middle two rational numbers if $\displaystyle {\frac{4}{7},\, \frac{1}{3},\, \frac{2}{5},\, \frac{5}{9}}$ are arranged in ascending order is:

  1. $\displaystyle \frac{86}{90}$

  2. $\displaystyle \frac{86}{45}$

  3. $\displaystyle \frac{43}{45}$

  4. $\displaystyle \frac{43}{90}$


Correct Option: D
Explanation:

$\displaystyle {\frac{4}{7},\, \frac{1}{3},\, \frac{2}{5},\, \frac{5}{9}}$
The above numbers in ascending order are
$\displaystyle {\frac{1}{3}\, <\, \frac{2}{5}\, <\, \frac{5}{9}\, <\, \frac{4}{7}}$
Middle two numbers are $\displaystyle \frac{2}{5}$ and $\displaystyle \frac{5}{9}$
$\therefore$ Average = $\displaystyle {\frac{2/5\, +\, 5/9}{2}\, =\, \frac{43}{90}}$

The given rational numbers are $\displaystyle {\frac{1}{2},\, \frac{4}{-5},\, \frac{-7}{8}}.$ If these numbers are arranged in the ascending order or descending order, then the middle number is:

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

  2. $\displaystyle \frac{-7}{8}$

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

  4. None of these


Correct Option: C
Explanation:

The rational number $\dfrac {4}{-5}$ is same as $\dfrac {-4}{5}$.


Now consider the given rational numbers $\dfrac {1}{2},\dfrac {-4}{5}$ and $\dfrac {-7}{8}$ and make their denominator same by taking the LCM of the denominators as follows:

LCM$(2,5,8)=40$

The given fractions now with denominator $40$ can be written as:

$\dfrac { 1\times 20 }{ 2\times 20 } =\dfrac { 20 }{ 40 } \ \dfrac { -4\times 8 }{ 5\times 8 } =\dfrac { -32 }{ 40 } \ \dfrac { -7\times 5 }{ 8\times 5 } =\dfrac { -35 }{ 40 }$ 

The ascending order of the rational numbers is:

$\dfrac { -35 }{ 40 } ,\dfrac { -32 }{ 40 } ,\dfrac { 20 }{ 40 } \ \Rightarrow \dfrac { -7 }{ 8 } ,\dfrac { 4 }{ -5 } ,\dfrac { 1 }{ 2 } .......(1)$

The descending order of the rational numbers is:

$\dfrac { 20 }{ 40 } ,\dfrac { -32 }{ 40 } ,\dfrac { -35 }{ 40 } \ \Rightarrow \dfrac { 1 }{ 2 } ,\dfrac { 4 }{ -5 } ,\dfrac { -7 }{ 8 } .......(2)$ 

From equations 1 and 2, we conclude that the middle rational number in both ascending and descending order is same that is $\dfrac {4}{-5}$.

Hence, the middle number is $\dfrac {4}{-5}$.