Final answer:
The shop limits its inventory investment to not exceed $30,000, and 250 workdays are used for business calculations instead of 365 days to account for weekends, holidays, and non-operational days.
Step-by-step explanation:
The question pertains to an inventory investment limitation in a shop context, where the shop never has more than $30,000 invested in the inventory. The second part of the question asks about the use of 250 workdays instead of 365 days in a year for a business calculation. The use of 250 workdays is based on the assumption that businesses generally operate on weekdays only, and it accounts for public holidays, weekends, and potential business closures, providing a more accurate depiction of a business's operational days within a year. It's a common practice in business calculations to use 250 work days to approximate a year's worth of business days as opposed to using the full 365 calendar days, which includes weekends and holidays when the business might not be operational.