math
posted by Seb .
A gift shop owner plans to give away calendars during the 31 days in January. Signs in her store say that the first 100 customers each day will receive a calendar. Should the owner estimate or find the exact product when placing her order for the calendars? Explain your reasoning.

Yes, but how many customers does she usually have in a day? Will some customers come in more than once in a month? If there are less that 100 customers/day, will all of them want a calendar?
These are some things to consider, but the data is not available on your post.