Question

at 5pm two hip started sailing toward each other from ports which were 300 miles apart at average rates of 20 and 25 mes per hour. at what time were the ships still 30 miles apart?

Answer 1

If the average rates were 20 and 25 miles per hour, then together they cover 45 miles of the distance they are separated by per hour.  The ships will be 30 miles apart when 270 miles have been covered, so it takes 270/45=6 hours to cover the distance.  6 hours after 5 PM is 11:00 PM.