Answer:
Pressure of liquid in container is given by, P= height × density × acceleration of gravity.
At the lower storey, the height of the liquid from the open end is great, since height is directly proportional to pressure, the pressure exerted by liquid is maximum hence increase in velocity of flow.
Unlike the upper storey where the height of water is less hence the pressure exerted by the liquid is minimum which decreases the velocity / speed of liquid flow