A biologist has two brine solutions, one containing 5% salt and another containing 20% salt. How many milliliters of each solution should she mix to obtain 1 L of a solution that contains 14% salt?
5% solution ___ mL
20% solution ___ mL
First thing is that there are 1000mL to each litre
So....we have this equation
(N ) (.05) + (1000 - N) (.20) = 1000(.14) simplify
.05N + 200 - .20N = 140
-.15N + 200 = 140 subtract 200 from both sides
-.15N = -60 divide both sides by -.15
N = 400 = mL of 5% solution
1000 - N = 1000 - 400 = 600mL of 20% solution