Question 567231
A pot contains 2 L of brine at a concentration of 100 g/L.
 How much of the water should be boiled off to increase the concentration to 200 g/L?
:
Convert 100g/L to 10% brine, which is .10
.10(2) = .20(2-w) 
.2 = .4 - .2w
.2w = .4 - .2 
.2w = .2
w = 1 liter should be boiled off
:
:
Check this
.10(2) = .20(2 - 1)
.2 = .2(1)