Posted by Jean on .
320ml of active ingredient is added to 680ml of an alcohol based solution. What is the final strength (v/v)? ___

Pharmacy Math 
DrBob222,
Use your other posts as a template.
% v/v is mL solute/total mL and you assume the volumes are additive (which isn't the usual case). 
Pharmacy Math 
Betty,
I have posted correctly

Pharmacy Math 
Terri,
320ml of active ingredient is added to 680 ml of an alcohol based solution. What is the final strength (v/v)?________