Hi:
This question is more of a SAS Programming 1 question, not a Data Science question. In the future if you have class questions, you might consider posting them in the forum that we have specfically for Programming 1 students. Here's that link for future reference: https://communities.sas.com/t5/Programming-1-and-2/bd-p/course_discussions .
For the problem that you're working on, our intention is to show students simple uses for macro variables. We start the practice slowly by making sure that the students have coded the correct WHERE statements and have them try the WHERE in 2 different procedures:
Then, after they have working code, we want them to keep going and define macro variables:
The purpose is to show the utility of macro variables and while building an entire WHERE condition is efficient, we didn't include that approach in the beginning Programmign course. We save something like that for the Macro 1 and Macro 2 courses.
Hope this helps explain our approach with this Practice and why there are 2 where statements.
Cynthia