Two trains are running with speed 30 km/hr. and 58km/hr. in the same direction. A man in the slower train passes the faster train in 18 seconds. The length (in metres) of the faster trains is: Select.
A) 70 B) 100 C) 128 D) 140 E) None of these
The relative speed = 58 - 30= 
<gadget id="calculator">58 - 30</gadget>
<output>28</output>
28 Km/hr.= 140/18 m/s.   Therefore in 18 secs the faster train travels = (140/18) * 18= 
<gadget id="calculator">(140/18) * 18</gadget>
<output>140</output>
140   Answer 140
<result>D</result>
Two trains are running with speed 30 km/hr. and 58km/hr. in the same direction. A man in the slower train passes the faster train in 18 seconds. The length (in metres) of the faster trains is: