This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Let us say when he heard the sound at    ( 30 + t ) sec .  It is more than 30sec because sound blasted after 30 sec and sound has to travel to reach the man.
By this time sound travelled :  t * 360 yrds    and man travelled  (30+t)*8 yrds
   So 360t = 8t + 240  => t = 15/22 sec.    So distance is 15*360/22 yrds