Joshua is scheduling a saving plan for his retirement in 10 years. In order to achieve his saving target, Joshua decided to invest $5,000 per month at the end of every month in a stock account and $80,000 per year at every year-end in a mutual fund account. The return on the stock account is expected to be 12% per annum (p.a.), and the mutual fund account will provide 9% p.a. return to him. (a) Joshua expects he will live 15 more years after his retirement. At the time he retires, he will combine the above investment money into a savings account which provides 6% p.a. monthly compounding interest income to him. Joshua wants to withdraw money at every month-end from this savings account during his 15 years retirement life. How much can Joshua withdraw each month during his retirement? (b) Following are the mathematical expression of the effective annual rate (EAR) and the annual percentage rate (APR): EAR (1r-1 APR rx m Where r is the period rate m is the number of period in a year Explain with basic finance concept and without calculation, what is the main difference between EAR and APR? Also, with the same period rate (r), under what special condition will make the two rates equal