A house is 19 ft tall. Its shadow is 30 ft long at the same time the shadow of a nearby building is 255 ft long. Find the height of the building.
David, the promoter of an outdoor concert, expects a net profit of $100,000, unless it rains, which would reduce the net profit to $25,000. The probability of rain is 0.20. For a premium of $23,000 David can purchase insurance coverage that would pay him $100,000 in case of rain. Find the expected net profit when the insurance is not purchased.