Subject: General Aptitude · Chapter: Time and Distance · Exam: 2009 · Marks: · Difficulty:
A bus started its journey from Ramgarh and reached Devgarh in 44 minutes at its average speed of 50 km/hr. If the average speed of the bus is increased by 5 km/hr, how much time will it take to cover the same distance?
(a)31 min
(b)36 min
(c)38 min
(d)40 min
(e)49 min
Answer
Answer (as printed): D
Explanation
Time taken to cover a distance is inversely proportional to the speed. Let the required time be $x$ min. Then, $50:55::x:44 \Leftrightarrow 55x=50\times44$ $$\Leftrightarrow x=\left(\frac{50\times44}{55}\right)\text{min}=40\text{ min}.$$
Explanation as extracted from the printed page; notation may be imperfect.