Subject: General Aptitude · Chapter: Time and Distance · Exam: 2008 · Marks: · Difficulty:
With an average speed of 50 km/hr, a train reaches its destination in time. If it goes with an average speed of 40 km/hr, it is late by 24 minutes. The total journey is
(a)30 km
(b)40 km
(c)70 km
(d)80 km
Answer
Answer (as printed): D
Explanation
Difference between timings $=24 \mathrm{min}=\frac{24}{60} \mathrm{hr}=\frac{2}{5} \mathrm{hr}$. Let the length of the journey be $x \mathrm{km}$. Then, $\frac{x}{40}-\frac{x}{50}=\frac{2}{5} \Leftrightarrow \frac{x}{200}=\frac{2}{5} \Leftrightarrow x=\left(\frac{2}{5} \times 200\right)=80 \mathrm{km}$.