Jimmy and his family are on their way to visit some family friends who live

780 miles away from them. based on the route they chose, they expect to

complete their trip in three days. the distances and average speeds for the

first two days driven are shown below.

• first day: 4 hours at an average speed of 60 miles per hour

• second day: 6 hours at an average 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?