Tag: more on proportion

Questions Related to more on proportion


select the missing number based on the given
$27: 65 :: 54: $____

  1. $130$

  2. $127$

  3. $126$

  4. $125$


Correct Option: A
Explanation:

$let\> the\> missing\> number\> be \>x \\ then\> (\frac{27}{65})=(\frac{54}{x})\\  \>x=(\frac{54\times 65}{27})\\= 130$

A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains $25$%. The percentage of water in the mixture is

  1. $4$%

  2. $6\frac { 1 }{ 4 } $%

  3. $20$%

  4. $25$%


Correct Option: C
Explanation:

According to the question,

Let's assume milkman has $100$ liter of milk, If he added $x$ liter of water, the percentage of water in the mixture$=\dfrac {x}{(100+x)}\times 100$

The milk gain $25$%, he must have added $25$ liter water in $100$ liter of milk. Then the percentage of water in the mixture$=\dfrac {25}{(100+25)}\times 100=20\%$


In the new mixture, If the milk is $80$% then $80$% of total mixture should be $100$ liter
$(100+x)\times \dfrac{80}{100}=100$
$8x=200$
$x=25$

Then, the percentage of water in the mixture $=\dfrac {25}{(100+25)}\times 100=20\%$