Let us solve the problem using an equation.
Let x be the speed of one of the boats.
The speed of the other boat will be x + 9.
Both the boats have traveled for 6 hours, starting from 12:00 noon to 6:pm
The distance they have traveled within 6 hours is 126 miles.
The distance traveled by the first boat is x*6 = 6x Miles
The distance traveled by the other boat is (x + 9) 6 = 6x + 54 Miles
Thus, 6x + 6x + 54 = 126 Miles
12x = 126 - 54
12x = 72
x = 72/12
x = 6
So the speed of one of the boats is 6 miles per hour and the speed of the other boats is 6 + 9 = 15 miles per hour.
