A) 72 km/h
B) 60 km/h
C) 54 km/h
D) 48 km/h
Correct Answer: B
Solution :
Time taken to cross the trains \[=\frac{150+100}{\frac{25}{3}+x}\] where x is the speed of second train. \[\Rightarrow \] \[10=\frac{250\times 3}{25+3x}\] \[\Rightarrow \] \[250+30x=750\] \[\Rightarrow \] \[30x=500\] \[\Rightarrow \] \[x=\frac{50}{3}m/s\] \[\therefore \] \[x=\frac{50}{3}\times \frac{18}{5}\] \[=60\,\text{km/h}\]You need to login to perform this action.
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