Q1 (#1)

hw3.sql:
- Implement Q1 query. Requires testing.
Q2 (#2)

hw3.sql:
- Implement Q2 query. Requires testing.
Q3 (#3)

hw3.sql:
- Implement Q3 query. Requires testing.
Q4 (#4)

hw3.sql:
- Implement Q4 query. Requires testing.
Q5 (#5)

hw3.sql:
- Implement Q5 query. Requires testing.