In a town, Khosla's formula is used to estimate runoff. If the monthly precipitation is recorded as 28 cm and the mean monthly temperature is 25°C, calculate the monthly runoff.

During the recuperation test of a 4 m open well, a recuperation of the depression head from 2.5 m to 1.25 m was found to take place in 2 hours. Determine the specific capacity per unit well area.

Rain gauge station X did not function for a part of the month during which a storm occurred. The storm produced rainfalls of 65, 80, 92 and 95 mm at four surrounding stations A, B, C and D, respectively. Estimate the missing rainfall at station X.