Problema Solution
How much water must be mixed with 7 pints of a solution that is 90% developer to produce a mixture that is 34% developer?
Answer provided by our tutors
Now we know that the amount of pure developer in the water that's added (0) plus the amount of pure developer in the 7 pints of 90% developer (0.50*7) has to equal the amount of pure developer in the final mixture(0.34(7+x)). So our equation to solve is:
0+0.50*7=0.34(7+x) get rid of parens
0.50*7=2.38+0.34x subtract 0.91 from each side
x = 3.29412 answer