An express train travelled at an average speed of 100 km/hr, stopping for 3 minutes after every 75 km. How long did it take to reach its destination 600 km from the starting point ?

A. 6 hr 21 min

B. 6 hr 24 min

C. 6 hr 27 min

D. 6 hr 30 min

Answer: Option A

Solution(By Examveda Team)

Time taken to cover 600 km
$$\eqalign{ & = \left( {\frac{{600}}{{100}}} \right)hr \cr & = 6hrs \cr} $$
Number of stoppages
$$\eqalign{ & = \frac{{600}}{{75}} - 1 \cr & = 7 \cr} $$
Total time of stoppages
= (3 × 7) min
= 21 min
Hence, total time taken = 6 hrs 21 min