Turnimal Construction builds four different types of housing development: flats, condominium, single story houses, and double story houses. Each type requires basic development in five different units:

Flat Condominium Single story Double story Days available

Plumbing 3 5 8 15 60

Electrical 8 10 15 24 90

Partition 34 40 60 120 520

Painting 14 20 25 39 190

Installation 5 14 29 42 70

Cost in RM'000 160 380 550 760

1. How many of each type of housing development should be developed to minimize cost?
2. If marketing requires that at least 20 units of each be developed, what is the optimal development plan and cost? How would you expect the cost to compare with your answer in (a)?
3. What happens if marketing requires that at least 30 units of each type be developed?