【答案解析】To make 3 gallons of the mixture requires 12 quarts, and the least amount of money is achieved by purchasing the greatest number of gallons and least number of quarts. Letting B be the number of quarts of blue paint needed and W be the number of quarts of white paint needed, it follows that B + W= 12, where B = 3W/2 since the mixture has a blue to white ratio of 3 to 2. This gives B=

and W=
