+127 how much pure water must be mixed with 2 pints of 90% developer to produce a mixture that is 32% developer?
+129852 Let's state everything in terms of water content......
90% developer = 10% water
32% developer = 68% water
Let x be the amount of pure water added to the 2 pints of 90% developer.......and we have
[pure water]* unknown amount of pure water + 2 pints of 10% water = final amount of 68% water
1x + .10(2) = (x + 2).68 multiply through to clear the decimals
100x + 10(2) = (x + 2)68 simplify
100x + 20 = 68x + 136 subtract 20 and 68x from both sides
32x = 116 divide both sides by 32
x = 3.625 pints of pure water
