Two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1.50 km and 1.25 km respectively. The time taken by the slower train to cross the faster train in seconds is? Choose the correct choice:
A) 12
B) 77
C) 66
D) 99
E) 11
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 = 1.50 + 1.25= 
<gadget id="calculator">1.50 + 1.25</gadget>
<output>2.75</output>
2.75 km= 2750 m.   Required time = 2750 * 3/125= 
<gadget id="calculator">2750 * 3/125</gadget>
<output>66</output>
66 sec.   Answer: 66
<result>C</result>
Two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1.50 km and 1.25 km respectively. The time taken by the slower train to cross the faster train in seconds is?