If employee a logged 120 hours of travel in four years and employee b logged hours of travel at a 20% higher rate, how many more hours did employee b have than employee a after 1.5 years?

Employee A in 4 years logged travel hours of = 120
Percentage more of travel hours logged by Employee B in 4 years = 20%
Then
Amount of travel hours logged by employee b in 4 years = (120/100) * 120
                                                                                           = 12 * 12
                                                                                           = 144 hours
Then amount of travel hours logged by Employee B after 1.5 years = (144/4) * 1.5
                                                                                                             = 216/4
                                                                                                             = 54 hours
Amount of travel hours logged by Employee A after 1.5 years = (120/4) * 1.5
                                                                                                  = 180/4
                                                                                                 = 45 hours.
Number of hours that Employee B had
than Employee A after 1.5 years = (54 - 45) hours
                                                     = 9 hours
So emplyee B had logged 9 hours more than Employee A after 1.5 years.