1. The problem involves understanding investment returns with given interest rates and durations. 2. The formula for simple interest is $$I = P \times r \times t$$ where $I$ is interest, $P$ is principal, $r$ is rate per period, and $t$ is time in periods. 3. For investments with cashback or buyback percentages, the total return is calculated as $$\text{Total} = P + (P \times r)$$ where $r$ is the cashback or buyback rate. 4. For example, for Dr. Anifade Johnson's investment of 500000 at 7% for 12 months, the interest is $$I = 500000 \times 0.07 \times 1 = 35000$$ and total amount is $$500000 + 35000 = 535000$$. 5. For Elizabeth Enitan Grace's cashback rollover at 40% for 12 months on 1,061,250, the total return is $$1,061,250 + (1,061,250 \times 0.40) = 1,061,250 + 424,500 = 1,485,750$$. 6. This method applies similarly to other entries with their respective rates and durations. 7. Understanding these calculations helps in evaluating investment growth over time.