207. 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 hrs 21 min
B. 6 hrs 24 min
C. 6 hrs 27 min
D. 6 hrs 30 min
✅ The correct answer is option A. 6 hrs 21 min.
Time taken to cover 600 km = ( 600/100 ) hrs = 6 hrs. Number of stoppages = ( 600/75 – 1 ) = 7 Total time of stoppage = (3 x 7) min = 21 min. Hence, total time taken = 6 hrs 21 min.

209. A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km /hr, the time taken by it to cover the same distance will be :__________?

A. 10 min
B. 11 min 20 sec
C. 13 min
D. 13 min 20 sec
✅ The correct answer is option D. 13 min 20 sec.
Speed = (10 X 60/12 ) km/hr = 50 km/hr. New speed = (50 – 5) km / hr = 45 km /hr. So Time taken = ( 10/45 ) hr = ( 2/9X 60 )min 131/3 min = 13 min 20 sec.