We can solve this problem by first calculating the annual net cash inflow. This can be solved by remembering that:
Payback period = Initial investment / Annual net cash inflow
6 years = $75,000 / Annual net cash inflow Therefore, Annual net cash inflow = $12,500 Next, we calculate for the cost. The cost we will consider here is the depreciation value of the machine. Annual depreciation = $75,000 / 15 years = $5,000 Therefore the annual net operating income is: Annual net operating income = $12,500 - $5,000 = $7,500 Simple rate of return is calculated by: Simple rate of return = Annual net operating income / Initial investment Simple rate of return = $7,500 / $75,000 = 0.1 = 10%