Bunuel wrote:
Solution X is 10 percent alcohol by volume, and solution Y is 30 percent alcohol by volume. How many milliliters of solution Y must be added to 200 milliliters of solution X to create a solution that is 25 percent alcohol by volume?
A. 250/3
B. 500/3
C. 400
D. 480
E. 600
Solution X = 200mL
Alcohol in Soln. X = 0.1 x 200 = 20mL
Solution Y = YmL
Alcohol in Soln. Y = 0.3YmL
Total Mixture = (200 + Y) mL
Alcohol in final Mixture = 0.25 x (200 + Y) = (50 + 0.25Y) mL
Now, Alcohol in Soln. X + Alcohol in Soln. Y = Alcohol in final Mixture
20 + 0.3Y = 50 + 0.25Y
0.05Y = 30
Y = 600
Hence, option E