A train met with an accident 120 km from station A. It completed the remaining journey at 5/6 of its previous speed and reached 2 hour late at station B. Had the accident taken place 300 km further, it would have been only 1 hour late. What is the speed of the train?

Answer: Option C

A ____100 km____ P₁ ________300 km_____ P₂ ____X______ B

If speed becomes $$\frac{5}{6}$$ then time taken will be $$\frac{6}{5}$$ of original time.
Thus, extra time = 2 hour
$$\frac{1}{5}$$ = 2 hour
Thus unusual time which is require to complete the journey = 5 × 2 = 10 hours.
It means It covers 300 km distance in 5 hours.
then speed = $$\frac{300}{5}$$ = 60 km/h