<PRE><B>Question 1013641</B>
Two trains are moving in opposite directions at the speed of 50km/hr and 70km/hr. Their lengths are 150m and 100m. The time required for their crossing each other is? 
----
Their crossing rate is 50+70 = 120km/hr
------
Their combined lengths is 150 + 100 m = 250 m
------
time = distance/rate = 250 m/120000m/hr = 0.0021 hr = 0.125 minutes = 7.5 sec
-----------
Cheers,
Stan H.
----------</PRE>