Answer:
The store owner must use 18 pounds of the 45 ¢ pasta.
Step-by-step explanation:
Given that a store owner has 12 pounds of pasta worth 70 ¢ a pound, and she wants to mix it with pasta worth 45 ¢ a pound so that the total mixture can be sold for 55 ¢ a pound, to determine how much of the 45 ¢ pasta must she use, the following calculation must be performed:
100 x 0.7 + 0 x 0.45 = 70
90 x 0.7 + 10 x 0.45 = 67.5
50 x 0.7 + 50 x 0.45 = 57.5
40 x 0.7 + 60 x 0.45 = 55
40 = 12
60 = X
60 x 12/40 = X
720/40 = X
18 = X
Thus, the store owner must use 18 pounds of the 45 ¢ pasta.
