Northampton City Tours (NCT) offers personalized historical and architectural tours in a large midwestern city and the local suburbs. NCT charges $352.00 per trip to or from the airport. The variable cost for a tour totals $43.00, for fuel, driver, and so on. The monthly fixed cost for NCT is $16,686. Required: a. How many tours must NCT sell every month to break even? b. NCT's owners believe that 60 tours is a reasonable forecast of the average monthly demand. What is the margin of safety in terms of the number of tours? (Round your answer to the nearest whole number.)