One of two alternatives will be selected to reduce flood damage in a rural community in central arizona. the estimates associated with each alternative are available. use b/c analysis at a discount rate of 10% per year over a 20-year study period to determine which alternative should be selected. for analysis purposes only, assume the flood damage would be prevented in years 3, 9, and 18 of the study period. retention pond channel initial cost, $ 880,000 1,500,000 annual maintenance , $/year 92,000 30,000 reduced flood damage, $ 200,000 625,000the δb/c ratio is?