Total fuel available overhead X (excluding reserves): 24,000 kg
Distance X to Y: 850 NM
Mean TAS (4 engines): 310 kt
Mean TAS (3 engines): 275 kt
Mean F/F (4 engines): 6500 kg/hr
Mean F/F (3 engines): 6350 kg/hr
Mean wind component out: -45 kt
Mean wind component home: +35 kt

The distance to the all engine operating Point of Equal Time between X and Y is: