Express train travel an average speed of 100 km/hour, taking the train 45 minutes to travel 75 km.
It will take the express train \(\frac{600}{75} = 8*45\) minutes per stretch of 75 km = 360 minutes

Additionally, it stops 3 minutes after it has traveled 75 km. This would add another 21 minutes
(7 times in total - after 75,150,225,300,375,450, and 525 km) to the total time spent to travel 600 km.

The time taken by the express train to travel 600 km is 381(360+21) minutes

We have been asked to find the distance covered by the local train in this time, provided it stops
a minute after traveling 25 kms(which will take it half an hour to travel at an average of 50 km/hr)

The time taken for the local train to travel 25 km is 31 minutes.

The total distance traveled by the local train is \(\frac{381}{31}*25 = 307.5\)(approximately) (Option C)
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Express train 600/75 = 8 *3 =24 hence Express train spent 24 minutes for all stops before it did 600 km. it means that it took express train 6 hours and 24 minutes to do 600 km.

Local train 600/25 = 24 min = 24 stops. 50 *6 = 300 km

since both trains spent 24 minutes on stops, these timings cancel out, so we are left with answer A

300 km did local train.

We are given that the express train traveled at an average speed of 100 kilometers per hour, stopping for 3 minutes after every 75 kilometers.

Let’s determine how many intervals of 75 km are in 600 km.

600/75 = 8

Since on the 8th interval the train will have stopped, the express train stopped for 3 x 7 = 21 minutes during the trip.

We also see that, without stopping, it takes the express train 6 hours to travel 600 km.

Thus, the total time spent by the express train was 6 hours and 21 minutes.

For the local train, we need to figure out how many minutes were spent on stopping in 6 hours and 21 minutes. Since the local train’s speed is 50 kmph and it travels every 25 km before it stops, it travels every 30 minutes before it stops. In 6 hours (ignoring the 21 minutes first), there are 12 intervals of 30 minutes and 11 stoppings of 1 minute, thus making a total of 6 hours and 11 minutes.

We see that we still have 10 minutes left to make up the 6 hours and 21 minutes. In these 10 minutes, the local train will stop for 1 minute first (after the 12th interval of 30-minute traveling) and then travels for 9 more minutes. Thus the actual travelling time of the local train (the time it’s moving) is 6 hours and 9 minutes, and during this time, it has traveled:

6 x 50 + 9/60 x 50 = 300 + 7.5 = 307.5 miles

Answer: C
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