kindly show all the workings

Question 3 Mr. Lutombi, aged 55 years old, is the current Roads Authority(RA) CEO. He is contemplating an early retirement and plans to invest his terminal benefits in Mobile Telecommunication Company (MTC) Namibia (MTC) and separate TELECOM Namibia (TELECOM) STOCK. Telecom is 100% government owned and was established in 1992 as a commercial subsidiary company of Namibia Post and Telecom Holdings Limited. TELECOM is serving more than 396000 (fixed and mobile) customers, with 986 employees and annual revenue of more than NS 1.5 Billion. MTC was established in 1994 and is mainly into mobile cellular business with over two million active subscribers and has a staff compliment of 421 . The following information relates to the two companies: Assuming: The market return is 12%, standard deviation of expected market return is 6%. Required: a. Calculate the standard deviation of returns of each service provider. (4 marks) b. Which service provider would you recommend for Mr. Lutombi to invest in? (3 marks) c. Assuming Mr. Lutombi invests 40% of his money in MTC and the rest in Telecom, what is Mr. Lutombi portfolio return