Complete Question
The complete question is shown on the first uploaded image
Answer:
The initial concentration is 
Explanation:
From the question we are told that
The volume of solution A is 
The concentration of A is 
The volume of solution B is 
The volume of water is
Generally the law of dilution is mathematically represented as

Where
is the concentration of the mixture
is the volume of the mixture which is mathematically evaluated as


So

substituting values


Note the mixture obtained is 