1. A small building can be re roofed for $6,000 with aluminum or $3,500 in asphalt shingles. The estimated life cycles are 50 years and 15 years respectively. If the interest rate is 10%, which alternative is superior?

2. A large sewer system will cost $175,000 annually. There will be a favorable benefit to the general public of $500,000 annually.

What is the benefit-cost ratio?

Should the project be constructed and why?