The difference in elevation equals subtraction. In other words 39ft subtracted by 8ft equals 31ft. So New Orleans, Louisiana is 31ft ABOVE sea level compared to EL Centro, California.
If a sprinkler system can water 5/8 acre of land in 1/4 hour, it can water 20/8 acre of a land in one hour. When turned into a mixed number you get that it can water 2 & 1/2 acres of land in 1 hour.
