Two goods trains each 720 m long are running in opposite directions on parallel tracks. Their speeds are 45 km/hr and 30 km/hr respectively. Find the time taken by the slower train to pass the driver of the faster one?
Select the correct option:
A) 22 sec B) 88 sec C) 48 sec D) 18 sec E) 72 sec
Relative speed = 45 + 30= 
<gadget id="calculator">45 + 30</gadget>
<output>75</output>
75 km/hr.   75 * 5/18= 125/6 m/sec.   Distance covered = 750 + 750= 
<gadget id="calculator">750 + 750</gadget>
<output>1_500</output>
1500 m.   Required time= 1500 * 6/125= 
<gadget id="calculator">1500 * 6/125</gadget>
<output>72</output>
72 sec.   Answer:72 sec
<result>E</result>
Two goods trains each 720 m long are running in opposite directions on parallel tracks. Their speeds are 45 km/hr and 30 km/hr respectively. Find the time taken by the slower train to pass the driver of the faster one?