Question 252618
Given,
      two boats left the North harbor at 4:30 Pm. One traveled east at a rate of 45kph,and the other west at 35 kph.
Their relative speed = 45+35 = 80kmph
The distance between the boats = 300kms
Time taken = Distance/relative speed
           = 300/80
           =3 3/4 hours
           = 3h 45m