John has been driving 60 miles an hour for 3 hours
The total distance to his destination is 240 miles
Since, D = R x T
Where, D = distance
R = rate
T = time
Since he drives 60 miles an hour, Then rate = 60/1
Rate = 60 miles/hour
From D= R x T
R = 60
T = 3
D = 60 x 3
D = 180 miles
John has traveled 180 miles for 3 hours.
Since his total destination is 240 miles
To calculate how much farther he needs to drive
Remaining distance = Total distance - Distance traveled in 3 hours
Remaining distance = 240 - 180
= 60 miles
John needs to travel 60 miles further before he can reach his final destination.