Word Problems

Question

How many milliliters of a 70% acid solution should be added to 12 milliliters of a 15% acid solution to obtain a solution that is 60% acid? 

 

 

Answer 1

Victoria,

 

To solve this, let x be ml of 70% acid solution. Then we set total amount of acid/total amount of liquid to be 60%.

 

(.7x+12(.15))/(x+12)=.6

.7x+1.8=.6x+7.2

.1x=5.4

x=54 ml

 

Checking our work:

54*.7+12*.15=37.8+1.8=39.6/(54+12)=.6 or 60% acid solution

 

Hope that helps!