Two guns were fired from the same place at an interval of 8 minutes. A person approaching the place observes that 5 minutes 52 seconds have elapsed between the hearing of the sound of the two guns. If the velocity of the sound is 330 m/sec, the man was approaching the place at what speed (in km/hr) ?

Let the speed of the man be x m/sec
Then, distance travelled by the man in 5 min 52 sec
= Distance travelled by sound in 8 sec
$$\eqalign{ & \Leftrightarrow x \times 352 = 330 \times 8 \cr & \Leftrightarrow x = \left( {\frac{{330 \times 8}}{{352}}} \right){\text{m/sec}} \cr & \Leftrightarrow x = \left( {\frac{{330 \times 8}}{{352}} \times \frac{{18}}{5}} \right){\text{km/hr}} \cr & \Leftrightarrow x = 27{\text{ km/hr}} \cr} $$