chemistry
posted by chi .
Potassium 2:5 Chloride solution 30ml. How many milliliters of a potassium chloride 3:5 solution do you need to prepare the order?

I asked earlier what you meant by a 2:5 and 3:5 solution and you didn't answer. I asked because there are several meanings to this. In my book a 2:5 solution is 40%(200/5) and a 3:5 solution is 60% (300/5).
So I use
c1v1 = c2v2
40*30 = 60*v2
v2 = 20
That is, add 20 mL of the 3:5 to a flask and add sufficient water to make 30 mL (10 mL) H2O to end up with 30 mL of 2:5 solution. 
so in other words DrBob, you dont know either