A truck covers a distance of 550 metres in 1 minute whereas a bus covers a distance of 33kms in 45minutes. The ratio of their speeds is?  Choose the correct answer.
A) 1 : 2  B) 3 : 4  C) 2 : 5  D) 3 : 7  E) 1 : 3

Rationale: ratio of speeds = ( 550 / 60 ) 18 / 5 : 60 * 33 / 45 = 33 : 44 = 3 : 4 answer is b
Answer: B