Question 793391
Let t = time it takes the police car to catch up to the speeding motorist.
During that time the speeder travels a distance d given by
(1)  d = 80t while the policy car travels that distance plus 3.5km or
(2) d + 3.5 = 148t
Put (1) into (2) to get
(3) 148t = 80t + 3.5 or
(4) 68t = 3.5 or
(5) t = 0.0514... 
Answer: The police car takes 0.0514+ hours to catch up to the speeder.