A dishonest milkman professes to sell milk at cost price but he mixes water into the milk and therefore he gains by 35%. Find ratio of mixture to water.

7 : 6 20 : 7 17: 6 7 : 16

20 : 7

Gain is because of added water CP  =  Milk Price SP – CP  =  Water added (Profit) 35%  =  \(\frac{7}{20}\)        Milk  :  Water   :     Mixture   13    :     7      :          20 Mixture  :  Water   =  20  :   7