A dishonest milkman sells his milk at cost price but he mixes it with water and thereby gains 25%.
What is the percentage of water in the mixture? Options:	A) 25%	B) 20%	C) 22%	D) 24%	E) None of these
Explanation :   --------------------------------------------------------------------------------Solution 1 - Using the concepts learned in   Profit and Loss--------------------------------------------------------------------------------If a trader professes to sell   his goods at cost price, but uses false weights, thenGain%=[Error(True Value−Error)×100]%Here Gain=   25%Here error = quantity of water he mixes in the milk = xHere the true value = true quantity of milk =   TSo the formula becomes 25 = x(T−x)×100⇒1=x(T−x)×4⇒T−x=4x⇒T=5xpercentage of water in the   mixture = xT×100=x5x×100=15×100=20%--------------------------------------------------------------------------------   Solution 2 - Using the concepts learned in Mixtures and Alligations---------------------------------------------------   -----------------------------Let CP of 1 litre milk = Rs.1Given that SP of 1 litre mixture = CP of 1 Litre milk =   Rs.1Given than Gain = 25%Hence CP of 1 litre mixture =   100(100+Gain%)×SP=100(100+25)×1=100125=45   20%y the rule of alligation, we have   CP of 1 litre milk CP of 1 litre water   1 0   CP of 1 litre mixture   4/5   4/5 - 0 = 4/5 1- 4/5 = 1/5   =&gt; Quantity of milk : Quantity of water = 4/5 : 1/5 = 4 : 1   Hence percentage of water in the mixture = 15×100=20%   Answer : Option 20%
<result>B</result>
A dishonest milkman sells his milk at cost price but he mixes it with water and thereby gains 25%.
What is the percentage of water in the mixture?