Answer:
The force is 

Step-by-step explanation:
From the question we are told that 
 The number of liquids is n = 3 
 The volume of the first liquid is 

 The density of the first liquid is 

 The volume of the second liquid is 

 The density of the second liquid is 
 
 
 The volume of the third liquid is 

 The density of the third liquid is 

Generally the force at the bottom of the container is mathematically represented as 
 

Here 

Here 
 is the total mass of all the liquid which is mathematically represented as
 is the total mass of all the liquid which is mathematically represented as 
 

=> 

=> 

So 
 

=> 

=> 

=> 
