Bunuel
A train met with an accident 150 km from its originating station. It completed the remaining journey at half of the usual speed and reached 1 hour late at the destination station. Had the accident taken place 30 km later, it would have been only half an hour late. Find the distance between the two stations.
A. 180 km
B. 200 km
C. 250 km
D. 400 km
E. None of these
Let the speed be 2x, so after accident speed is x..
If remaining distance is y,
then time taken normally =\( \frac{150+y}{2x}\), but time taken now = \(\frac{150}{2x}+\frac{y}{x}\), so \(\frac{150}{2x}+\frac{y}{x}-\frac{150+y}{2x}=1........\frac{y}{x}-\frac{y}{2x}=1......y=2x\)
Now the remaining distance is y-30,
then time taken normally = \(\frac{180+y-30}{2x}\), but time taken now =\( \frac{180}{2x}+\frac{y-30}{x}\), so \(\frac{180}{2x}+\frac{y-30}{x}-\frac{180+y-30}{2x}=1........\frac{y-30}{x}-\frac{y-30}{2x}=\frac{1}{2}......y-30=x...y=x+30\)
Equating values of y..\(y=2x=x+30...x=30,\) and \(y=2*30=60\)..Total distance =\( 150+60=210..\)
E
Logically too... By travelling 30 km at original speed rather than half the speed, the train saves half an hour....
So to save the entire 1 hour, the train should have traveled 30*2 or 60 km at original speed.This means the total distance is 150+60=210
E