c) You are working on a project to develop a new or enhanced system to help people at your college, university or organization to find jobs. The system must be tailored to your student or work population and be very easy to use. Write a short notes describing how you would collect requirements for this system, and include at least five requirements in a requirements traceability matrix.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?