GV is a small accounting firm supporting wealthy individuals in their preparation of annual income tax statements. Every December, GV sends out a short survey to their customers, asking for the information required for preparing the tax statements. Based on 50 years of experience, GV categorizes their cases into the following groups:

• Group 1 (new customers, easy): 15 percent of cases
• Group 2 (new customers, complex): 5 percent of cases
• Group 3 (repeat customers, easy): 50 percent of cases
• Group 4 (repeat customers, complex): 30 percent of cases

Here, “easy” versus “complex” refers to the complexity of the customer’s earning situation.

In order to prepare the income tax statement, GV needs to complete the following set of activities. Processing times (and even which activities need to be carried out) depend on which group a tax statement falls into. All of the following processing times are expressed in minutes per income tax statement.