Mohammad Holding is a manufacturer of camping trailers based in Mount Druitt, Sydney, nearly 70 per cent of the company's out put is exported to New Zealand Fiji island and Indonesia. The fixed costs are $200,000 per annum and the variable costs are $500 per trailer. The trailers are sold for $800 each. Currently 2,000 trailers are made and sold in a year. Calculate net margin of safety in units and as percentage % *