Question

Doreen schmidt is a chemist. she needs to prepare 3232 ouncesounces of a 1010​% hydrochloric acid solution. find the amount of 1616​% solution and the amount of 88​% solution she should mix to get this solution.

Answer 1

24 ounces of 8% solution and 8 ounces of 16% solution to create 32 ounces of 10% solution.  
OK. We need 32 ounces of 10% solution and we have 16% and 8% solutions available. So let's set up an equation to solve. I'll use the variable X to represent the amount of 8% solution needed. 
X*0.08 + (32-X)*0.16 = 32*0.10 
 Now simplify and solve.
 X*0.08 + (32-X)*0.16 = 32*0.10
 X*0.08 + 32*0.16 - X*0.16 = 32*0.10
 X*0.08 - X*0.16 = 32*0.10 - 32*0.16
 X(0.08 - 0.16) = 32(0.10 - 0.16)
 X(-0.08) = 32(-0.06)
 X = 32(-0.06)/(-0.08)
 X = 24 
 So we need 24 ounces of 8% solution and (32 - 24) = 8 ounces of 16% solution.