A track covers a distance of 550 metres in 1 minute whereas a bus covers a distance of 33 kms in 45 minute. The ratio of their speeds is:

Answer: Option C

Speed of track = 550 per minute.
Speed of bus = $$\frac{33\text{kms}}{45}$$   = $$\frac{33000}{45}$$  = 733.33 m/minute
Ratio of their speeds = $$\frac{550}{733.33}$$  = 3 : 4