A constant-head test was conducted on a sample of soil 15cm long and 60 cm^2 in cross-sectional area. The quantiities of water collected was 50 cm^3 in 20 seconds undera a head difference of 24 cm. Calculate the hydraulic conductivity. If the porosity of sand is 55%, calculate the average velocity and the seepage velocity. Estimate the hydraulic conductivity of a similar soil with a porosity of 35% from the results test.