Problema Solution
A pharmacist wishes to mix a solution that is 7% Minoxidil. She has on hand 70 ml of a 2% solution and wishes to add some 9% solution to obtain the desired 7% solution. How much 9% solution she add?
Answer provided by our tutors
The "percent solution" is the amount of minoxidil divided by the total volume. Let 'v' be the amount of 9% to add. Then we have (0.09*v+70*0.02)/(v+70)=0.07. This gives v=175. We can check the answer by making sure 2% of 70 plus 9% of 'v' is equal to 7% of 70+v.