Question

A store owner has 12 pounds of pasta worth 70¢ a pound. She wants to mix it with

pasta worth 45¢ a pound so that the total mixture can be sold for 55¢ a pound
(without any gain or loss). How much of the 45¢ pasta must she use?

Answer 1

The store owner must use 18 pounds of the 45 ¢ pasta.

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.