How do I solve the below in excel?

You received a big contract from a multi-billion firm to analyze its efficiency. They provided you with data on one output produced from one input for five of their branches (oil wells), which are the decision making units (DMUs), where the same technology was utilized, yet apparently at different levels of efficiency. The data is summarized in Table 1 Use this data and the material learnt in the lectures and tutorials to answer the following questions: Table 1: Input-output data for 5 Branch A Branch B Branch C Branch D Branch E Input x (bln. $) 20 20 50 100 40 Output y (min. barrels) 20 40 60 80 40 1. Formulate (mathematically) a constant-returns-to-scale (CRS) DEA model in envelopment form that can be used to determine the Farrell's output-oriented technical efficiency (OTE) for a general input-output alloca- tion (x, y). (20 marks)