- Alligation:It is the rule that enables us to find the ratio in which two or more ingredients at the given price must be mixed to produce a mixture of desired price.
- Mean Price:The cost of a unit quantity of the mixture is called the mean price.
- Rule of Alligation:If two ingredients are mixed, then
Quantity of cheaper 
= C.P. of dearer – Mean Price Quantity of dearer Mean price – C.P. of cheaper We present as under:
C.P. of a unit quantity
of cheaperC.P. of a unit quantity
of dearer(c) Mean Price
(m)(d) (d – m) (m – c) 
(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.
After n operations, the quantity of pure liquid = 
x 1 – y n 
units. x
Tips and Tricks on Alligation
5x + 24 = 40 – 5x
