A) 14 km/h
B) 42 km/h
C) 50.4 km/h
D) 67.2 km/h
Correct Answer: C
Solution :
Let the length of the train be x m. \[\therefore \]\[\frac{x+162}{18}=\frac{x+120}{15}=\]speed of the train \[\Rightarrow \] \[\frac{x+162}{6}=\frac{x+120}{5}\] \[\Rightarrow \] \[6x+720=5x+810\] \[\Rightarrow \] \[x=810-720=90\] \[\therefore \] Speed of the train\[=\frac{90+162}{18}\,\,m/s\] \[=\frac{252}{18}\times \frac{18}{5}\,\,km/h\] = 50.4 km /hYou need to login to perform this action.
You will be redirected in
3 sec