A motorcyclist goes from Bombay to Pune, a distance of 180 kms at an average of 20 kmph speed. Another man starts from Bombay by car 2 Â½ hours after the first, and reaches Pune Â½ hour earlier. What is the ratio of the speed of the motorcycle and the car?  Choose one:
A) 1 : 2  B) 2 : 3  C) 1 : 9  D) 1 : 5  E) 1 : 1

Rationale: "t = 180 / 20 = 9 h t = 9 - 3 = 6 time ratio = 9 : 6 = 3 : 2 speed ratio = 2 : 3 answer : b"
Answer: B