Subject: General Aptitude · Chapter: Time and Distance · Exam: 2007 · Marks: · Difficulty:
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)?
(a)24
(b)27
(c)30
(d)36
Answer
Answer (as printed): B
Explanation
Let the speed of the man be $x \mathrm{m} / \mathrm{sec}$. Then, Distance travelled by the man in 5 min 52 sec = Distance travelled by sound in 8 sec $\Leftrightarrow x \times 352=330 \times 8$ $\Leftrightarrow x=\left(\frac{330 \times 8}{352}\right) \mathrm{m} / \mathrm{sec}$. $$=\left(\frac{330 \times 8}{352} \times \frac{18}{5}\right) \mathrm{km} / \mathrm{hr}=27 \mathrm{km} / \mathrm{hr} .$$