Answer:
Quantity of solution B required is 300 ml
Step-by-step explanation:
Let "a" be quantity of solution A required
Let "b" be quantity of solution B required
We are given Solution A is 19% alcohol and Solution B is 14% alcohol and that the resulting mixture has 156 milliliters of pure alcohol
Thus;
0.19a + 0.14b = 156 - - - (eq 1)
Also, He uses twice as much Solution A as Solution B.
Thus;
a = 2b
Putting 2b for a in eq 1 gives;
0.19(2b) + 0.14b = 156
0.38b + 0.14b = 156
0.52b = 156
b = 156/0.52
b = 300 ml
Quantity of solution B required is 300 ml