a factory owner purchases two types of machines,a and b for his facorythe area occupied by machines a and b are 1000 sqm and 1200 sqm respectively. machine A requires 12 mens and machine B requires 8 men to operate it.the daily output of machine A and B are 60 units and 40 units respectively the owner has an area of 9000m^ available and 72 skilled men who can operate the machine how many machines of each type should he buy to maximise the daily output