In 1 kg mixture of iron and manganese 20% of manganese. How much iron should be added so that
the proportion of manganese becomes 10%
Select
A) 1.5 Kg	B) 2 Kg	C) .5 Kg	D) 1 Kg	E) None of these
Explanation :   By the rule of alligation, we have   Percentage concentration of   manganese in the mixture : 20 Percentage concentration of   manganese in pure iron : 0   Percentage concentration of manganese in the final mixture   10   10 - 0= 
<gadget id="calculator">10 - 0</gadget>
<output>10</output>
10 20 - 10= 10   =&gt; Quantity of the mixture : Quantity of iron = 10 : 10 = 1 : 1   Given that Quantity of the mixture = 1 Kg   Hence Quantity of iron to be added = 1 Kg   Answer : Option 1 Kg
<result>D</result>
In 1 kg mixture of iron and manganese 20% of manganese. How much iron should be added so that
the proportion of manganese becomes 10%