Tag: maths

Questions Related to maths

First, third and the fourth terms of a proportion are $6, 12$ and $36$ respectively. Then the second term is :

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

  1. $12$

  2. $18$

  3. $16$

  4. $108$

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Correct Option: B
Explanation:

$6 : x : : 12 : 36$


$\therefore$ $\frac{6}{x}=\frac{12}{36}$


$\therefore$ $x\, =\, \displaystyle \frac{6\, \times\, 36\,}{12}\, =\, 18$.


the second term is  $18$.

Find the fourth proportional to $2.4, 4.6$ and $7.6$?

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

  1. $14$

  2. $14.657$

  3. $15.56$

  4. $14.56$

Show answer
Correct Option: D
Explanation:
Let the fourth proportional be $x$

$ \therefore \dfrac{2.4}{4.6} = \dfrac{7.6}{x}$

$\Rightarrow x=\dfrac{7.6 \times 4.6}{2.4}$

$\Rightarrow x=14.56$

Fill in the blank so that the three numbers will be in proportion ___, $32$, $64$.

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

  1. $36$

  2. $18$

  3. $16$

  4. $15$

Show answer
Correct Option: C
Explanation:

$x : 32 : : 32 : 64 $


$\therefore$ $\frac{x}{32}=\frac{32}{64}$

$\therefore$  $x\, =\, \displaystyle \frac{32\,\times\, 32}{64}\,=\,16$.


A fruit salad is made from pineapples, pears, and peaches mixed in the ratio of $2$ to $3$ to $5$, respectively, by weight. What fraction of the mixture by weight is pineapple?

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

  1. $\dfrac{1}{5}$

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

  3. $\dfrac{2}{5}$

  4. $\dfrac{1}{2}$

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

Show answer
Correct Option: A
Explanation:
Given,
A fruit salad is made from pineapples,pears and peaches mixed in the ratio $2:3:5$ respectively by weight
total weight of mixture as per ratio is $\left( 2+3+5 \right) =10$
Fraction of weight in  mixture  pineapple will be $\dfrac { 2 }{ 10 } =\dfrac { 1 }{ 5 } $

First, second and the third terms of a proportion are $5, 120$ and $40$ respectively. Then the fourth term is :

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

  1. $89$

  2. $480$

  3. $960$

  4. $98$

Show answer
Correct Option: C
Explanation:

$5 : 120 : : 40 : x$


$\therefore$ $\frac{5}{120}=\frac{40}{x}$

$\therefore$  $x\, =\, \displaystyle \frac{120\, \times\, 40\,}{5}\, =\, 960$.

In a family, the father took $\displaystyle\frac{1}{4}$ of the cake and he had $3$ times as much as each of the other members had. The total number of family members is ___________.

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

  1. $3$

  2. $7$

  3. $10$

  4. $12$

Show answer
Correct Option: C
Explanation:
Let the number of family members $=x$

fraction of cake the father took $=\dfrac{1}{4}$

fraction of cake  other members had $ =\dfrac{3}{4}$

fraction of cake  EACH  other members had $ =\dfrac{3}{4(x-1)}$

given that :
fraction of cake the father took was 3 times   as much as each of the other members had.
$\Rightarrow  \dfrac{1}{4}=3 \times \dfrac{3}{4(x-1)}$

$\Rightarrow x-1 = 9$
$\Rightarrow x = 10 $

the number of family members are  $=10$


If the fourth proportional of $7\cfrac { 1 }{ 5 } ,4\cfrac { 1 }{ 5 } $ abd $3\cfrac { 6 }{ 7 } $ is k, Then $\cfrac { 4k+1 }{ 4k-1 } =$

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

  1. $\cfrac { 4 }{ 5 } $

  2. $\cfrac { 6 }{ 5 } $

  3. $\cfrac { 7 }{ 5 } $

  4. $\cfrac { 5 }{ 4 } $

Show answer
Correct Option: A

$23:\dfrac {506}{6}::31:?$

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

  1. $\dfrac {931}{6}$

  2. $\dfrac {630}{3}$

  3. $\dfrac {938}{12}$

  4. $\dfrac {930}{3}$

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Correct Option: A

Mark the correct alternative of the following.
If $80 : 60 =x :12$, then $x=?$

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

  1. $16$

  2. $7$

  3. $24$

  4. $50$

Show answer
Correct Option: A
Explanation:

Given,

$80:60=x:12$
or, $\dfrac{80}{60}=\dfrac{x}{12}$
or, $x^2=\dfrac{8}{6}\times 12$
or, $x=16$.

Mark the correct alternative of the following.
If $4 : 5 : : x : 45$, then $x=?$

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

  1. $54$

  2. $60$

  3. $36$

  4. $30$

Show answer
Correct Option: C
Explanation:

Given, $4:5:: x:45$

or, $\dfrac{4}{5}=\dfrac{x}{45}$
or, $x=\dfrac{4}{5}\times 45$
or, $x=4\times 9$
or, $x=36$.