7. Below is the Trial Balance of Manson Kotobre Company on 31st May, 2013. b) Provision for depreciation on plant and machinery should be 20% per annum on cost c) Profit margin on manufactured goods is at the rate of 10% on cost of production. 7. Below is the Trial Balance of Manson Kotobre Company on 31st May, 2013. b) Provision for depreciation on plant and machinery should be 20% per annum on cost c) Profit margin on manufactured goods is at the rate of 10% on cost of production