Answer:
1,200 ml of water must be added
Step-by-step explanation:
Let
x ----> the amount of water needed in ml
we know that
In a 8% solution, the amount of water is 92%
so
[tex]400(0.92)=368\ ml[/tex]
In a 2% solution the amount of water must be 98%
so
[tex](400+x)0.98=368+x[/tex]
solve for x
[tex]392+0.98x=368+x\\x-0.98x=392-368\\0.02x=24\\x=1,200\ ml[/tex]