A milkman wants to gain 25% on selling the mixture at cost price, then in what ratio must he mix water with milk?

Question: A milkman wants to gain 25% on selling the mixture at cost price, then in what ratio must he mix water with milk?

Solution:
Let, the milkman has milk of 100 Tk.
after mixing he sold it in = 100 + 25 = 125 Tk.

In 125, milk is of 100 Tk. and water is of 25 Tk.

∴ The ratio of water and milk is 25 : 100 = 1 : 4