Subject: General Aptitude · Chapter: Problems on Trains · Exam: · Marks: · Difficulty:
A train moving at 15 m/sec takes 20 seconds to pass a cyclist moving in the same direction as that of the train. How much time will the train need to pass the cyclist, if the cyclist moves in a direction opposite to that of the train and if the speed of the cyclist is 5 m/ sec and the length of the cycle is 1 m?
(a)9.95 sec
(b)10 sec
(c)10.05 sec
(d)12 sec
Answer
Answer (as printed): B
Explanation
Let the length of the train be $x$ metres. Then, distance covered in passing the cyclist $=(x+1) \mathrm{m}$. $$\begin{aligned} & \therefore x+1=(15-5) \times 20=200 \Leftrightarrow x=199 \mathrm{m} . \\ & \text { So, required time }=\left[\frac{(x+1)}{15+5}\right] \text { sec }=\left(\frac{200}{20}\right) \text { sec }=10 \text { sec. } \end{aligned}$$