A boiler delivers steam at 100 bar and 500 °C (h = 3375 kJ/kg). The feed water enters at 160 °C (take h_{fw} ≈ 4.187 × t). Steam is produced at 100 tonnes per hour and the boiler efficiency is 88 %. If the calorific value of the fuel is 21 MJ/kg, estimate the fuel burning rate (answer in kg/h).