(a) You are interested in a retirement investment plan that you recently discussed with your Personal Banker. The investment plan offers the following returns:

For the 1st RM20,000 you invest, you will get a return of 20 percent next year ,

For the 2nd RM20,000 you invest, you will get a return of 17 percent next year,

For the 3rd RM20,000 you invest, you will get a return of 14 percent next year ,

For the 4th RM20,000 you invest, you will get a return of 11 percent next year ,

For the 5th RM20,000 you invest, you will get a return of 8 percent next year ,

Based on your portfolio, you noticed that you have RM100,000 fixed deposit maturing that you should be able to use for the retirement plan. However, you have to pay for an operation that you undergoing last month. The bill amount is RM50,000. If the current rate of interest is 10 percent p.a., based on the Fisher's Theorem how can you optimise your investment and consumption decision?