Any help is greatly appreciated:

A data warehouse of a telephone provider consists of five dimensions:

caller customer, callee customer, time, call type, and call program

and

three measures: number of calls, duration, and amount.

Define the OLAP operations to be performed in order to answer the following queries. Propose the dimension hierarchies when needed.

(a) Total amount collected by each call program in 2012.

(b) Total duration of calls made by customers from Brussels in 2012.

(c) Total number of weekend calls made by customers from Brussels to customers in Antwerp in 2012.

(d) Total duration of international calls started by customers in Belgium in 2012.

(e) Total amount collected from customers in Brussels who are enrolled in the corporate program in 2012.