3. (20) You are planning to build a toll bridge and charge cars and trucks for driving across it. You must decide whether to build a 2-lane bridge or a 4-lane bridge (you get more traffic with 4 lanes). Due to construction techniques, the 4-lane bridge will also last longer. The data and lifetimes of the two bridges are given below The associated costs, revenues and useful lives are given in the table below. At the end of their useful life, both bridges are sold for $100,000. Two lane bridge ($1000's) Four lane bridge (S1000's) Total Initial Cost 650 1.000 Total Annual Operating Cost 200 Total Annual Revenue 450 600 Salvage 100 100 - Useful Life 6 years 12 vears a. (13) Assuming repeatability, compare these two alternatives using an equivalent worth method assuming the MARR is 10%. Indicate which alternative is preferable. b. (7) Compare these two alternatives using a coterminated approach with a 6-year study period. Indicate which alternative is preferable