Question 438068
How many liter of pure hydrochloric acid must be added to 60 liters of solution 
that is 10% hydrochloric acid to get a solution that is 15% hydrochloric acid?
:
Let x = amt of pure acid required
:
.10(60) + x = .15(x+60)
:
6 + x = .15x + 9
x - .15x = 9 - 6
.85x = 3
x = {{{3/.85}}}
x ~ 3.53 liters of pure acid