A simple economy is based on 3 commodities: grain, fuel and transportation.
Production of 1 unit of grain requires 1/4 unit of fuel and 1/3 unit of transportation
Production of 1 unit of fuel requires 1/2 unit of grain and 1/4 unit of transportation,
Production of 1 unit of transportation requires 1/4 unit of grain and 1/4 unit of fuel.
Find the input-output matrix for this situation and the gross output required for a net production of 516 units of grain, 258 units of fuel and 129 units of transportation.