Health Sing, who is dieting, requires two food supplements: I and II. He can get these supplements from two different products. A and B, as shown in the table,

Grams of Supplement per Serving

III

Product A 3 2

B 2 4

Sing's physician has recommended that he include at least 15 g of each supplement in his daily diet. If product A costs 25 cent per serving and product B costs 40 cents per serving. How can he satisfy his dietetic requirement most economically? Find the minimum cost.