Retired grandparents expect to spend $500 each year for the next two years to cover Christmas presents for their grand kids.
Due to increasing costs, the couple expects to spend $550 three years from now, $600 the next year, and $650 the year after.
However, due to their medical needs, they hope to need to spend $300 per year after that.
Draw this cash flow diagram for a total of fifteen years using an interest rate of 10% per year.