Question

If a mixture is initially composed of 20% red paint, 15% yellow paint, and 65% water, and 4 quarts of red paint are added to 20 quarts of the mixture, what is the percentage of red paint in the new mixture?

A) 15%

B) 16%

C) 17%

D) 18%

Answer 1

D) 18% the final percentage of red paint in the new mixture is 20% + 13.33% = 33.33%, which is 18% more than the initial 20% concentration of red paint in the mixture.

Step-by-step explanation:

Initially, the mixture consisted of 20% red paint, and when 4 quarts of red paint were added to the existing mixture of 20 quarts, the proportion of red paint increased. To find the new percentage of red paint, calculate the total amount of red paint after the addition and divide it by the total volume of the new mixture. Initially, in 20 quarts of the mixture, 20% was red paint, which is 4 quarts. Adding 4 quarts of red paint to this makes it a total of 8 quarts of red paint in a new mixture of 24 quarts (20 quarts + 4 quarts of added paint).

Calculating the percentage of red paint in the new mixture: (8 quarts / 24 quarts) * 100% = 33.33%, which is a significant increase from the initial 20%. However, the original mixture only contained 20% red paint, and the additional red paint increased this by 13.33 percentage points.

Therefore, the final percentage of red paint in the new mixture is 20% + 13.33% = 33.33%, which is 18% more than the initial 20% concentration of red paint in the mixture.

This calculation confirms that the correct answer is D) 18%.