A manufacturer wishes to mix two brands of drink so that the ingredient per litre of the mixture is at least 18 units of iron, 14 units of calcium and 20 units of alcohol. The ingredient per litre of the brand one is 4 units of iron, 2 units of calcium and 2 units of alcohol. The ingredient per litre of brand two is 2 units of iron, 2 units of calcium and 4 units of alcohol. One litre of brand one costs shs.10 and one litre of brand two costs shs.14.

- Form inequalities representing the above information
- Represent the inequalities on the grid provided
- From the graph, determine the minimum cost per litre of the new brand of drink obtained by mixing brand one with brand two.