I know it's not a math problem, but I didn't know where else to ask for help.

The question goes like this:

A motorist travelling at 105 km/hr is being chased by a police car at 149 km/hr. If the police car starts from 5.0 km back, how long does it take to catch the motorist? Leave time in hours.

I tried 10 different things but nothing seems to give me a reasonable answer.

Any help/tips appreciated.