You are here
MIXTURE AND ALLIGATION FORMULA CAT Concepts Courses Format MBA Quantitative Aptitude XAT 



What is a Mixture?


mixture contains two or more ingredients of certain of certain quantity mixed together to get the desired quantity. This quantity is expressed as ratios or percentage.

Mixture is when two varieties of rice are mixed to form a new variety of rice.

What is an Alligation?


 Two ingredients A and B of price x and y respectively are mixed and the price of the resultant mixture is M (mean price), the ratio (R) in which ingredients are mixed is called, the rule of the alligation


An alligation is the rule that enables us to find the ratio where two or more ingredients at a given price or value should mix to produce a mixture at a given price (Value or Strength).


Formulas for Mixtures and alligation questions 


Pictorial representation of Mixtures and Alligation

Example 1Mixtures and Alligation Questions

Question: How much salt at 42 paise/kg will mix with 25kg salt at 24 paise/kg, to earn a profit of 25% by selling the mixture at 40 paise /kg?


Th question is based on a combination of two different varieties of salt to obtain a mixture at the given price.

In this question, we have to find the quantity of salt costing 42 paise i.e., mixed.

So, we need to find the ratios of the quantity to find the quantity of salt i.e., mixed.

Step 1:

First, we need to find the price of the mixed salt, that is

Profit = 25%

Selling Price = 40 paise/kg

Cost of the Mixture = 32 paise

Step 2:

Use the pictorial representation method to find the ratios.

Step 3:

The ratio = 4 : 5

Quantity(dearer) : Quantity (Cheaper) = 4 : 5

Again, Quantity(dearer) : 25 = 4 : 5

Furthermore, Quantity(dearer) x 5 = 4 x 25

Then, Quantity(dearer) = 100/5

And at last, Quantity(dearer) = 20kg

Hence, To make a new salt mixture, 20kg of dearer quantity will be mixed with 25kg of cheaper quantity

Example 2: Mixtures and Alligation Questions 


Question: A merchant has 840kg of rice, part of which he sells at 9% profit and the rest at 16% profit. He must gain 12% profit on the whole. Find the quantity sold at 16% profit?


Step 1:

By applying the alligation rule on the profit percentages

Step 2:

Quantity (sold at 9% profit): Quantity (sold at 16% profit) = 4 : 3

840: Quantity (sold at 16% profit) = 4 : 3

Quantity (sold at 16% profit) = (3 / 7) x 840 (by the basis of ratio and proportion, we need to take the whole part i.e. 4 + 3 = 7)

Quantity (sold at 16% profit) = 360Kg.

Hence, It incur 16% profit to sell 360 kg

Do write in the comment section how this blog helped you to solve mixtures and alligation questions using mixture and alligation formula.

Don't miss out!
Subscribe To Newsletter

Receive top CAT Exam tips and more

Invalid email address
Give it a try. You can unsubscribe at any time.



Related posts

Leave a Comment