to find how long the trip will take, you first divide the number of miles she has already driven and divide by the time it has taken to get that far to get the unit rate,
216 miles/ 4 hours= 54 miles/ hour. Next take the number of total miles she has to drive and divide that by the unit rate you found earlier, 486 miles/ 54 mph , to get how long the entire trip will take her to complete, 486/ 54= 9 hours total. so she has only 5 hours left to drive
