In order to determine how log will take for 8 people to pave a driveway you use the given proportion: 3 people pave a driveway in 4 hours.
By a simple rule of three you have:
3/4 = 8/x
Where you have peeple in the numerator and time in hours in the denominator.
You solve the previous equation for x:
3/4 = 8/x
x = (8/3)*(4) = 32/3 = 10.66
Then, 8 people will take approximately 10 hours plus 40 minutes to pave a driveway