Question 1165977
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A non-algebraic approach....<br>
You are starting with 50% developer and adding 0% developer (pure water), stopping when you get to 32%.<br>
From 50 to 32 is a difference of 18; from 50 to 0 is a difference of 50.<br>
So you are stopping adding water 18/50 = 9/25 of the way from 50% to 0%.<br>
That means 9/25 of the final mixture is the water you are adding; that means 16/25 of the mixture is the 50% developer you started with.<br>
So 16/25 of the mixture was 4 pints; that means the 9/25 of the mixture that is water is 9/16 of 4 pints, or 9/4 = 2.25 pints.<br>
ANSWER: Add 2.25 pints of pure water.<br>
CHECK:
.50(4)+0(2.25) = 2+0 = 2
.32(4+2.25) = .32(6.25) = 2<br>