Question 644410
in a chemistry lab, stephanie has to make a 37 milliliter solution that is 12% HCL. All that is in the lab is 8% and 15%. How many mL of each solution should she use to obtain the desired amount?
.
Let x = amount (mL) of 8%
then
37-x = amount (mL) of 15%
.
.08x + .15(37-x) = .12(37)
.08x + 5.55-.15x = 4.44
5.55-.07x = 4.44
-.07x = -1.11
x = -1.11/(-.07)
x = 15.86 mL (8%)
.
15%:
37-x = 37-15.86 =  21.14 mL