Question 549907
How much pure water must be mixed with 3 pints of 70% developer to produce a mixture that is 29% developer? 
:
Let x = amt of water required
:
.7(3) = .29(x+3)
2.1 = .29x + .87
2.1 - .87 = .29x
1.23 = .29x
x = 1.23/.29
x = 4.24 pints of water required
:
Check this by finding the amt of developer in each mixture, should be the same
.7(3) = .29(3+4.24)
2.1 = .29(7.24)
2.1 = 2.1; confirms our answer of 4.24 pts of water