Please Solve these 4 Questions and show the workout.

Thanks in advance.

5. Gibson plans to fund his individual retirement account, beginning today, with 20 annual deposits of $4.000, which he will continue for the next 15 years. If he can earn an annual compound rate of 8 percent on his deposits, what will be the amount in the account upon retirement? 6. You have been offered a project paying $3,200 at the beginning of each year for the next 20 years. What is the maximum amount of money you would invest in this project if you expect 6 percent rate of return to your investment? 7. In their meeting with their advisor, Mr. and Mrs. Abbas concluded that they would need $30,000 per year during their retirement years in order to live comfortably. They will retire 10 years from now and expect a 20-year retirement period. How much should Mr. and Mrs. Abbas deposit now in a bank account paying 7 percent to reach financial happiness during retirement? 8. A generous philanthropist plans to make a one-time endowment to a renowned heart research center which would provide the facility with $320,000 per year into perpetuity. The rate of interest is expected to be 7 percent for all future time periods. How large must the endowment be