Alligation Q3

3. In what ratio must water to be mixed with milk to gain 20% by selling the mixture at cost price?

Solution: Let the C.P of milk be Re 1 per liter

Then S.P of 1 liter of mixture = Re.1

Gain obtained =20%.

Therefore C.P of 1 liter mixture = Rs(100/120*1) =5/6

C.P of 1 liter of water  0     C.P of 1 liter of milk1

                    Mean Price 5/6

         1/6                          5/6

Ratio of water and milk =1/6 : 5/6 = 1:5.