An electric cooperative is considering the use o f a concrete electric pole in the expansion of its power distribution lines. A concrete pole costs 18,000 each and will last 20 years. The company is presently using creosoted wooden poles which cost 12,000 per pole and will last 10 years. If money is worth 12 percent, which ole should be used? Assume annual taxes amount to 1 percent of first cost and zero salvage value in both cases. Determine the best alternative using: (i = 12%)

a. Rate of Return on Additional Investment Method

b. Annual Cost (AC) Method

c. Equivalent Uniform Annual Cost (EUAC) Method

d. Present Worth Cost (PWC)