In what ratio must water be mixed with milk to gain 40% by selling the mixture at the cost price of milk?

2:5 5:2 5:7 2:7

2:5

Let CP of milk be Re.1 per liter = SP of the mixture Gain % = 30% So CP of mixture = Rs (10/13) per liter let C = Rs. 0 /liter , D = Rs. 1 / liter and M = Rs.(10/14) / liter Then the ratio of mixes is (D-M): (M-C