Confusing isn't it !!
In a drip irrigation system water flows at 0.4 m/s through a 25 mm diameter pipe. At each of the plants in the field water is expected to be delivered at 0.02 m/s through a 2 mm opening. The drip works for 2 hours a day. Then,
(a) the system feeds 2250 plants.
(b) a plant gets about 3.2 litres of water a day.
(c) the system feeds 3125 plants.
(d) a plant gets about 1.8 litres of water a day.