sorry for reposting this but im really stuck

Question

Simpson drives his car with an Vavg of 48.0 km/h to the east. how long will it take him to drive 144 km on a straight highway?
i got the answer to that as 3 hours
but i cant do this: how much time would he save by increasing his Vavg to 56.0 km/h to the east?
the answer is 0.43 hours
but i get 2.57 hours: time=distance/rate so; t=144/56

where am i going wrong???

Answer 1

Think. The question is not how long it takes him if he speeds up, but how much time will he save.

3.0hrs-2.57hrs=.43hrs