Answer:
a. 9.2
Explanation:
Pe = (P - 2S) ^2 / (P + 0.8S) ^2
The run off is the speed of meting of snow or water after rainfall. In the given scenario the precipitation is almost 9.2 in which is the runoff. The urban area has 20 acres of lawn which is considered as S in the equation. After solving the equation for runoff we get 9.2in.
Pe = (P - 2S) ^2 / (P + 0.8S) ^2
Pe = (75 - 2 *20) ^2 / (98 + 0.8 *12) ^2
Pe = 9.2
