Answer:
(speeds) plane = 84, wind is 28
Step-by-step explanation:
when with wind: 672/6 = 112
so: speed(plane) + speed(wind) = 112
when against wind: 672/12 = 56
so: speed(plane) - speed(wind) = 56
add both eq to get: 2 speed(plane) = 168
speed(plane) = 84
therefore speed(wind) = 28
