Mathematics · Relational Database Concepts

A database architect is classifying the Cardinality Ratios of 60 distinct relationships in an enterprise ER schema based on their exact conceptual characteristics: - 25 relationships: 'Students ↔ Courses' - 18 relationships: 'Department → Employees' - 12 relationships: 'Person ↔ Passport' - 5 relationships: 'Students → Advisor' Let P = Many-to-Many (M:N) relationships count. Let Q = One-to-Many (1:N) relationships count. Let R = One-to-One (1:1) relationships count. Let S = Many-to-One (N:1) relationships count. Calculate the value of: (P × Q) - (R × S).