A centrifugal pump running at 1000 rpm delivers 160 L/s against a head of 30 m. The atmospheric pressure is 100 kPa (abs) and the vapour pressure of water is 3 kPa (abs). The head loss in the suction pipe is 0.2 m. Using Thoma's critical cavitation factor σ_{c} = 1.03 × 10^{−3} N_{s}^{4/3} (N_{s} = N√Q/H^{3/4}, rpm, m^{3}/s, m), calculate (a) the minimum NPSH (m) and (b) the maximum height of the pump above the sump (m).