Difficult Math Problem #16

600 = 8 * 75

so there were 7 stopps of 3 minutes and 8 rides that took (75/100)*60 = 45 min

total jurney was 8*45+21 = 381 min

the local train takes 30min to pass 25Km + 1minute

so 381/31 = 12*31 + 8 minute

so the local train would pass 12*25 + (8/60)*50 =~ 306.6

* if i would add to this 3 minute, i would get 307.5, but i think the accurate answer is 300.666

so: C

i ment 306.666 ...

i ment 382/31 = 12 + 9 min

and (9/60)*50 = 7.5

so the answer is indeed: 307.5

final post from me on this thread

600/75 = 8 so the train in all had to come across 7 stations by the last 8th station it covered the 600 kilometers so no halting time.

7stations * 3mins = 21 mins THe total time the train halted

75 kms it covers in 45 mins , which is the journey for 1 station
so in all 45 *8 = 360 mins

In all time 360 +21 = 381

For local train,
50kmph so it travels 25 kmph in 30 mins + a 1 min break
so in 31 mins it travels 25 km

mins - km
31 - 25
381 - x

so x= 381*25/31= ~ 307[Anyone knows a better way to calculate this]

OR a better way to solve this. Btw Ans C

clarification:

381/31 = 12 and a reminder of 9 (which are 9 minutes)

the local train drives at 50km/h so in 9 minutes it will pass:

(9/60)*50 = 7.5 km

OA:

the answer is C: 307.5 km
Express Train:
600 km --> 6 hours (since 100 km/h) + stops * 3 min.
stops = 600 / 75 = 8, but as it is an integer number, the last stop in km 600 is not a real stop, so it would be 7 stops
so, time= 6 hours + 7 * 3 min. = 6 hours 21 min

Local Train:
in 6 hours, it will make 300 km (since its speed is 50 km/hour)
in 300 km it will have 300 / 25 stops = 12, 12 stops 1 min each = 12 min
we have 6 hours 12 min, but we need to calculate how many km can it make in 6 hours 21 min, so 21-12 = 9 min
if 60 min it can make 50 km, 9 min it can make 7.5 km
so, the distance is 300 + 7.5 = 307.5 km