Distance = 1920
Time = 6
Speed = 320km/hour
Return
Distance = 1920
Time = 3 1/3 hours
Speed = 1920/ 3 1/3 = 1920 x 3/10 = 576km/ hour
Let the actual speed of jet be a and wind be b
a - b = 320
a + b = 576
Add
2a = 896
a = 448
448 - b = 320
b = 448- 320 = 128km/hour