can i please get help with the rational formula question bellow, I just wanted to know what steps were taken to get to the solution. i don't understand how or why c=0.65 or why A=4.5 and 5.5 A grassed block of land 10 hectares in size of medium drainage is to be developed into a residential housing development. There are two possible options being assessed by the developer. The developers preferred option is to subdivide the entire property into housing (10 ha)(Option One). However the council want the flow from the catchment to be no more than 150% of predevelopment level (Option Two). Therefore an area of the catchment must be re-vegetated in native bush and mulched. Using the Rational Formula calculate the total quantity of flow (Q) from both the existing grassland-Option One (C = 0.30), and Option Two where a certain area of the catchment will need to be sized for re-vegetation in native bush (C = 0.2) to meet the council requirements (State this land area based on 150 % of predevelopment flow and the flow (Q) from each of the 2 areas) . An intensity of 40 mm/hr has been provided by the council for the design return period rainfall of 5 years. A suitable ‘C’ value for the completed urban development must be used in the calculations. Q = kCIA Where k = 2.78 (for l/s) For the farmland C = 0.30 = 2.78 x0.30 x 40 x 10 = 333.60 l/s Post development 150 % = 500.40 l/s For Option One development C= 0.65 = 2.78 x 0.65 x 40 x 10 = 722.8 l/s For Option Two development C= 0.65 = 2.78 x 0.65 x 40 x 5.5 = 397.5 l/s For Option Two development reveg area C= 0.20 = 2.78 x 0.20 x 40 x 4.5 = 100.1 l/s Revegetation area = 4.5 ha