Given that the ship was traveling for 4 mph faster heading west than south then let the speed of the ship heading south be x mph, the speed of the ship heading west will be (x+4) mph
the distance is given by:
distance=speed*time
distance heading south was:
x*4=4x miles
distance heading west was:
5(x+4)=5x+20
thus the total distance will be given by:
4x+(5x+20)=191
9x+20=191
9x=191-20
9x=171
x=171/9
x=19 mph
the speed the ship used to travel west was:
x+4
=19+4
=21 mph
