question_answer

A man standing between two parallel hills fires a gun and hears two echoes, one 2.5 s and the other 3.5 s after the firing. If the velocity of sound is \[330\,\,m{{s}^{-1}}\], how long will it take him to hear the third echo? [NDA]

A) 4 s                   

B) 5 s

C) 6 s                    

D) 8 s