The drainage area upstream of a small dam is 20 acres. On a certainday the pond was 9 feet deep with a surface area of 1.6 acres. That night, a 5.4 inch rainstorm caused a large rise in the pond. The next morning, the pond was 12 feet deep with a surface area of 2.4acres. There was no outflow from the pond during this period. Find:
a) Volume of runoff from the land surface into the pond, inacre-feet
b) Depth of runoff from the land surface, in inches