Jimmy and his family are on their way to visit some family friends who live 780 miles away from them. the distances and average speeds for the first days driven are first day 4 hours at a speed of 60 miles per hour and the second day 6 hours at a speed of 65 miles per hour. if the average speed on the third day is 60 miles per hour, how many more hours will it take for them to reach their family friends' home?