Answer:
7 packages
Step-by-step explanation:
Given that Mr. Wilkins wants 525 paper plates for the school picnic.
And there are 75 plates in each package at the grocery store.
What is the number N of packages he should buy is equal the number of paper plate needed divided by the number of plates in each package.
Therefore, Mr. Wilkins should buy 7 packages for the school picnic.