Imagine the door to a theatre is opened and you are standing outside. how is it possible that you can hear the sound of the movie or play even if you cannot see the screen or stage ?
a) reflection only happens with sound waves not waves of light so the sound waves bounce out to your ears.
b) the sound waves refract as they move from one medium to another
c) the darkness in the theatre absorbed light but not sound so you can hear
d) the sound waves diffract much more than the light waves so try bend and spread as they move through the doorway.

D) the sound waves diffract much more than the light waves so try bend and spread as they move through the doorway.

Explanation:

Since we know that wavelength of sound is more so the diffraction phenomenon of sound is much easier and possible way to get the sound in all possible direction

Diffraction phenomenon is possible only when the opening of the size is of order of the wavelength of sound

so here we can easily hear the sound coming from the theater and since the light is of shorter wavelength so we can not see the image as it will not show any diffraction from that size of opening

the total distance traveled by the car is

30km + 49km = 79 km .