A pharmacy has determined that a healthy person should receive 70 units of proteins, 100 units of carbohydrates and 20 units of fat daily. If the store carries the six types of health food with their ingredients as shown in the table below, what blend of foods satisfies the requirements at minimum cost to the pharmacy? Make a mathematical model for the given problem.

Foods
Protein units
Carbohydrates units
Fat units
Cost per unit

A
20
50
4
2

B
30
30
9
3

C
40
20
11
5

D
40
25
10
6

E
45
50
9
8

F
30
20
10
8


A local manufacturing firm produces four different metal products, each of which must be machined, polished and assembled. The specific time requirements (in hours) for each product are as follows: