Answer:
The simple rate of return is closest to 87.1%
Step-by-step explanation:
To calculate the rate of return, we will determine first determine the net return on investment on the machine after 10 years as follows:
cost of maintenance per year = $28,000
cost of maintenance for 10 years (expenditure) = 28,000 × 10 = $280,000
Labor savings per year = $60,000
Labor savings for 10 years ( income) = 60,000 × 10 = $600,000
Net income after 10 years = Total income - total expenditure
= 600,000 - 280,000 = $320,000
Next, we will determine the cost of investment as shown below:
cost of new machine = $190,000
scrap value of old machine = $19,000
Net cost of machine = 190,000 - 19,000 = $171,000
Therefore, the net return on investment is calculated as:
Net return on investment = Net income - cost of machine
= 320,000 - 171,000 = $149,000
Finally the rate of return in percentage, is calculated as follows:
rate of return = [(Net return on investment) ÷ (cost of investment) ] × 100
= ( 149,000 ÷ 171,000 ) × 100 = 87.1% (to 1 decimal place).