1. Assuming a ratio of two ingredients is used and the Mean Price, the cost price per unit quantity of the mixture, is known. Quantity of cheaper/ Quantity of dearer = CP of Dearer – Mean Price / Mean Price – CP of cheaper.
2. Mean Price: The cost of a unit quantity of the mixture is called the mean price. (Cheaper quantity) : (Dearer quantity) = (d - m) : (m - c). Suppose a container contains x of liquid from which y units are taken out and replaced by water.
3. The rule of alligation enables us to find the ratio in which two or more ingredients at the given price must be mixed to produce a mixture of a desired price. This technique can be applied to any topic like mixtures, profit & loss, simple interest, time & distance, percentage, etc.