You are given an economy with three sectors only, namely; Service (S), industry (I) and agriculture (A). The service sector uses 30 ngwee of its own output and 50 ngwee of industry output to produce a kwacha worth of output. The industry needs 20 ngwee from the service sector, 30 ngwee of its own output and 40 ngwee from agriculture to produce a kwacha worth of output. The agriculture needs 40 ngwee of service sector, 20 ngwee from the industry and 20 ngwee of its own output to produce a kwacha worth of output. The open sector demands K SOO worth of output from the service sector and Kl 000 worth of agriculture output.