Two alloys, A and B are made from four metals I, II, III and IV according to the following specifications:

Alloy	Specifications	Selling price ($)
A	At most 80% of I At most 30% of II At least 50% of IV	200
B	Between 40 and 60% of II At least 30% of III At most 70% of IV	300

The four metals are, in turn, are extracted from three ores according to the following data.

		Constituents (%)
Ore	Max. quantity (tons)	I	II	III	IV	Others	Price/ton ($)
1	1000	20	10	30	30	10	30
2	2000	10	20	30	30	10	40
3	3000	5	5	70	20	0	50

_{Formulate this problem as a linear program.}