Answer:
0.81
Explanation:
Present Value of annual Maintenance cost = $20,000 / 6% = $333,333.33
In five year time, $200,000 is required as major maintenance cost. So effective rate for 5 year = [(1 + 6%) ^ 5] - 1 = 1.3382 - 1 = 0.3382 = 33.82%. Present Value of 5 year cost = $200,000 / 33.82% = $200,000 / 0.3382 = $591,366.06
Total Present Value cost = $2,800,000 + $333,333.33 + $591,366.06 = $3,724,699.39.
Annual Cost = $3,724,699.39 * 6% = $223,481.96.
Benefit / Cost = $180,000 / $223,481.96
Benefit / Cost = 0.805434138845032
Benefit / Cost = 0.81
So, conventional B/C ratio is 0.81.