A new highway is to be constructed. Design A calls for a concrete pavement costing $75 per foot with a 12-year life; two paved ditches costing $5 per foot each; and two box culverts every mile, each costing $9,000 and having a 12-year life. Annual maintenance will cost $1,800 per mile; the culverts must be cleaned every three years at a cost of $300 each per mile. Design B calls for a bituminous pavement costing $30 per foot with a 6-year life; three sodded ditches costing $1.50 per foot each; and two pipe culverts every mile, each costing $2,300 and having a 6-year life. The replacement culverts will cost $2,400 each. Annual maintenance will cost $2,700 per mile; the culverts must be cleaned yearly at a cost of $235 each per mile; and the annual ditch maintenance will cost $1.35 per foot per ditch. Compare the two designs on the basis of equivalent worth per mile for a 12-year period. Find the most economical design on the basis of AW and PW if the MARR is 10% per year. The AW value for Design A is $n /mi The PW value for Design A is $ /mi The AW value for Design B is $/mi The PW value for Design B is $/mi The most economical design on the basis of AW and PW is ASAP PLZ