Question 541108
The boats are converging at the sum of their speeds.
Boat 1 is going at speed = x
Boat 2 is going at speed = x+9
In 6 hrs (noon to 6 p.m.) they travel 126 miles.
d = r*t
126 = r * 6
r = 126/6 = 21
.
Their combined speeds are x+x+9 = 2x+9
.
2x+9 = 21
2x = 12
x = 6 mph = speed of the slower boat
x+9 = 15 mph = speed of the faster boat
.
To check, how far does each travel in 6 hr?
6*6 = 36
6*15 = 90
36+90 = 126
.
Done.