Air-Breathing & Rocket Propulsion

An ideal turbofan with a bypass ratio of 5 has core mass flow rate, ṁ a,c= 100 kg/s. The core and the fan exhausts are separate and optimally expanded. The core exhaust speed is 600 m/s and the fan exhaust speed is 120 m/s. If the fuel mass flow rate is negligible in comparison to ṁ a,c, the static specific thrust (T/ṁ a,c) developed by the engine is ____ Ns/kg (rounded off to the nearest integer).