Two roadway designs are under consideration for access to a permanent suspension bridge. Design 1A will cost $2.9 million to build and $225,000 per year to maintain. Design 1B will cost $3.6 million to build and $40,000 per year to maintain. Both designs are assumed to be permanent. Use an AW-based rate of return equation to determine (a) the breakeven ROR and (b) which design is preferred at an MARR of 20% per year.

a) The breakeven ROR is

%.

b) At an MARR of 20% per year, design

(Click to select) 1B 1A

is preferred.