If a train runs at 40 kmph, it reaches its destination late by 11 minutes but if it runs at 50 kmph, it is late by 5 min only. The correct time for the train to complete its journey is :

A. 13 min

B. 15 min

C. 19 min

D. 21 min

Answer: Option C

Solution(By Examveda Team)

Let the correct time to complete the journey be x min
Distance covered in (x + 11) min at 40 kmph
= Distance covered in (x + 5) min at 50 kmph
$$\eqalign{ & \therefore \frac{{\left( {x + 11} \right)}}{{60}} \times 40 = \frac{{\left( {x + 5} \right)}}{{60}} \times 50 \cr & \Leftrightarrow x = 19{\text{ min}} \cr} $$