unit 1 ratio & mixture

            ALLIGATION OR MIXTURES

Important Facts and Formula:

1.Allegation:It is the rule that enables us to find the

ratio in which two of more

ingredients at the given price must be

mixed to produce a mixture of a desired price.

2.Mean Price:The cost price of a unit quantity of the mixture

is called the mean price.

3.Rule of Allegation:If two ingredients are mixed then

          Quantity of Cheaper / Quantity of Dearer =
                             (C.P of Dearer – Mean Price) /(Mean Price–C.P of Cheaper).

                           C.P of a unit quantity of cheaper(c)
                           C.P of unit quantity of dearer(d)
                           Mean Price(m)
                               
                          (d-m) (m-c)

 Cheaper quantity:Dearer quantity = (d-m):(m-c)
 
4.Suppose a container contains x units of liquid from which y units
are taken out and replaced by water. After n operations the
quantity of pure liquid = x (1 – y/x)n units.
 
SOLVED PROBLEMS

Simple problems:
1.In what ratio must rice at Rs 9.30 per Kg be mixed with rice
at Rs 10.80 per Kg so that the mixture be worth Rs 10 per Kg?
Solution:
C.P of 1 Kg rice of 1st kind 930 p C.P of 1 Kg rice of 2n d kind 1080p
Mean Price 1000p
80 70