Two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 1.9 km respectively. The time taken by the slower train to cross the faster train in seconds is? Choose one:
A) 99
B) 72
C) 48
D) 96
E) 22
Relative speed = 60 + 90= 
<gadget id="calculator">60 + 90</gadget>
<output>150</output>
150 km/hr.= 150 * 5/18 = 125/3 m/sec.   Distance covered = 1.10 + 1.9= 
<gadget id="calculator">1.10 + 1.9</gadget>
<output>3</output>
3 km= 3000 m.   Required time = 3000 * 3/125= 
<gadget id="calculator">3000 * 3/125</gadget>
<output>72</output>
72 sec.   Answer:72
<result>B</result>
Two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 1.9 km respectively. The time taken by the slower train to cross the faster train in seconds is?