Subject: General Aptitude · Chapter: Time and Distance · Exam: · Marks: · Difficulty:
A thief running at 8 km/hr is chased by a policeman whose speed is 10 km/hr. If the thief is 100 metres ahead of the policeman, then the time required for the policeman to catch the thief will be
(a)2 minutes
(b)3 minutes
(c)6 minutes
(d)10 minutes
Answer
Answer (as printed): B
Explanation
Relative speed $=(10-8) \mathrm{km} / \mathrm{hr}=2 \mathrm{km} / \mathrm{hr}$. Required time = Time taken to cover 100 m at relative speed $$=\left(\frac{100}{2000}\right) \mathrm{hr}=\frac{1}{20} \mathrm{hr}=\left(\frac{1}{20} \times 60\right) \mathrm{min}=3 \mathrm{min} .$$