Karen places a bet with Tom that she will beat Tom in a car race by 4 miles even if Karen starts 4 minutes late. Assuming that Karen drives at an average speed of 60 mph and Tom drives at an average speed of 45 mph, how many Q miles will Tom drive before Karen wins the bet?  Choose one:
A) 15  B) 18  C) 21  D) 24  E) 27

Rationale: "let k and t be the speeds of karen and tom respectively . t be the time that karen will travel - - - - > t + 4 / 60 will be the total time tom will travel by the time the distance between karen and tom is 4 miles . thus , per the question , k ( t ) - t ( t + 4 / 60 ) = 4 - - - > t = 7 / 15 hours thus the distance traveled by tom when karen is 4 miles ahead of him : t * ( t + 4 / 60 ) = 45 ( 7 / 15 + 4 / 60 ) q = 24 miles . d is the correct answer ."
Answer: D