Question 1047306
In the lab, Heather has two solutions that contain alcohol and is mixing them with each other. 
She uses 500 milliliters less of Solution A than Solution B.
 Solution A is 17% alcohol and 
 Solution B is 11% alcohol.
 How many milliliters of Solution A does she use, if the resulting mixture has
167 milliliters of pure alcohol?
:
a = amt of A solution
b = amt of B solution
"500 milliliters less of Solution A than Solution B."
a = b - 500
:
A mixture equation
.17a + .11b = 167
Replace a with (b-500)
.17(b-500) + .11b = 167
.17b - 85 + .11b = 167
.17b + .11b = 167 + 85
.28b = 252
b = 252/,28
b = 900 ml of B solution used
therefore
900 - 500 = 400 ml of A solution
:
;
Check by finding the actual amt of alcohol in each
.17(400) = 68 ml
.11(900) = 99
------------------------
total alcohol: 167 mo