4. A local county is considering purchasing some dump trucks for the trash pickups. Each truck will cost $55,000 and have an operating and maintenance cost that starts at $18,000 the first year and increases by $3,000 per year. Assume the salvage value is $12,000 at the end of 5 years and the interest rate is 10%. The equivalent annual cost of owning and operating each truck is most nearly. a. $35,974 b. $32,600 c. $37,939 d.$6,956 6. Consider the following two mutually exclusive projects. Select the best project based on the IRR criterion. Assume a MARR at 10% End of Year Project Al Project AZ -$3,000 -$1,000 $1.300 $500 $1,500 $1,000 $1,000 $1,000 $2,000 $2,000 10.815 41.42%