*8. Students at U of A have expressed dissatisfaction with the fast pace at which the math department is teaching the one-semester Call. To cope with this problem, the math department is now offering Call in 4 modules. Students will set their individual pace for each module and, when ready, will take a test that will elevate them to the next module.

The tests are given once every 4 weeks, so that a diligent student can complete all 4 modules in one semester. After a couple of years with this self-paced program, it is observed that for the first module 20% of the students do not complete it on time. The percentages for modules 2 through 4 are 22%,25%, and 30%, respectively.

(a) Express the problem as a Markov chain.