Answer: The speed of the aircraft carriers would be 28.33 mph.
Explanation:
Since we have given that 
Distance between the ships = 100 miles
Speed of the fishing boat = 5 mph
Number of hours = 6 hours
Let the speed of an air craft carrier be 'x'.
Since they are in opposite direction, so, our equation would be 

Hence, the speed of the aircraft carriers would be 28.33 mph.