A certain masonry dam requires 500,000 cu.m. of gravel for its construction. The contractor found two possible sources for the gravel with the following data: Source A Source B Average distance, gravel pit to dam 4.0 km 1.0 km site Gravel cost/cu.m. at pit P415.00 Purchase price of pit P800,000.00 Road construction necessary P450,000.00 None Overburden to be removed at 80,000 cu.m. P50.00/cu.m. Hauling cost per cu.m. per km P7.00 P7.00 Which of the two sites will give lesser cost