4. (1) Given is a three-pipe series system, as in the figure. The total pressure drop is PA-PB = 150 kPa, and the elevation drop is -2 = 5 m. The pipe data are Pipe L, m D, cm €, mm 1 100 8 0.24 2 150 6 0.12 3 80 4 0.20 Calculate the flow rate Qin m³/s through the system, neglecting minor losses. (2) Assume that the same three pipes in the problem above (problem 4) are now in parallel with the same total head loss of 20.32 m. Compute the total flow rate in m³/s, neglecting minor losses.