<PRE><B>Question 475768</B>
Scientists in a chemistry lab have 75 ml of pure acid which must be diluted to a solution that is 10% acid. 
How many milliliters of water should they add?
:
Let x = amt of water required
:
75 = .10(x+75)
75 = .10x = 7.5
75 - 7.5 = .10x
67.5 = .10x
x = {{{67.5/.1}}}
x = 675 ml of water required
:
:
Check
75 = .10(675+75)
75 = .10(750)</PRE>