A train moving on a straight horizontal track with constant speed $$108\,\mathrm{km/h}$$ approaches a hill. When the engine is $$1200\,\mathrm{m}$$ from the hill, it produces a whistle of frequency $$550\,\mathrm{Hz}$$. Assuming the speed of sound is $$330\,\mathrm{m/s}$$, choose the correct options

A

The echo from the hill will be heard by the driver after $$1/9\,\mathrm{min}$$

B

The distance of the engine from the hill when the echo is heard is $$1000\,\mathrm{m}$$

C

The wavelength of the sound produced by the whistle is $$60\,\mathrm{cm}$$

D

The echo from the hill will be heard by the driver after $$20/3\,\mathrm{s}$$