A thin-walled double-pipe counter-flow exchanger cools oil (c_{p} = 2200 J/kg·°C) from 150 °C to 40 °C at 2 kg/s using water (c_{p} = 4180 J/kg·°C) entering at 22 °C at 1.5 kg/s. Find (a) the water exit temperature and (b) the LMTD (answers in °C).