M4maths Previous Puzzles

11 Aug 2017 Trains

Two trains are running in opposite directions on parallel tracks. Train running with speed 60 Km/hr has 240 meter length and the second train running with speed of 40km/hr has 290 meter length.
What is the time taken by the faster train to completely pass through the length of slower train (i.e from front to rear)?

OPtion

1) 17.50 seconds
2) 10.44 seconds
3) 19.80 seconds
4) 19.02 seconds
5) 10.80 seconds
6) 19.50 seconds
7) 18.80 seconds
8) 19.90 seconds
9) 19.08 seconds
10) None of these

Solution

Relative speed= 60+40 = 100 km/hr = 100 * 5/18 = 250/9 m/sec

We are calculating the time taken by the faster train to completely pass the length of slower one.
Hence, distance = length of the slower train + length of faster train = 240+290 = 530 meter

Time = 530/250/9 = 19.08 seconds

Correct Option: 9 Best Solution (6)

SAYAN CHATTERJEE   7 years AGO

relative velocity = (60+40) = 100 kmph
total distance to be travelled= (290+240) = 530
So, time reqd. = (530/1000)/ 100= 0.0053 hr.
= 0.0053*3600 secs.
= 19.08 secs.
Option 9.

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Ravi   7 years AGO

t=D1+D2/S1+S2
t=240+290/(60+40)/5/18=477/25
so t= 19.08sec

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G.S.Kantharao   7 years AGO

Relative speed=60+40=100kmph
Speed Per Second=100*5/18=500/18
Relative length =240+290=530
Time taken to cross=530*18/500=19.08 sec.
Hence my option is 9👈

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D Annapoorna   7 years AGO

time to be taken=530×18÷100×5=19.08

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Madhuvani v   7 years AGO

Relative speed=(60+40) km/hr = 100 km/hr
= (100*5/18)m/sec = 250/9 m/sec
distance covered = (240+290) m = 530 m
required time = (530*9/250) sec = 19.08 sec

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Mukund Manohar   7 years AGO

Relative Speed of the train = (60+40) = 100 km/hr = 500/18 m/s
Required Time = Sum of length of trains/Relative Speed
= (240+290) / (500/18) = 530/ (500/18) = 19.08 seconds

Like? Yes | No