1. A test was carried out on a wine filter. It was found that under a constant pressure difference of 350 kPa gauge, the rate of flow was 450 kg h^-1 from a total filter area of 0.82 m². Assuming that the quantity of cake is insignificant in changing the resistance of the filter, if another filter of 6.5 m² area is added, what pressure would be required for a throughput of 500 hectolitres per 8-hour shift from the combined plant? Assume the density of the wine is the same as that of water (15 points).