CDS Government Jobs Exams

two trains each 100m long moving in opposite directions , cross each other in 8 seconds. if one is moving twice as fast the other then the speed of the faster train is:

1) 30 kmph
2) 45 kmph
3) 60 kmph
4) 75 kmph

Read Solution (Total 3)

ANS; 60 Km/hr

Let the speed of the slower train be x m/sec.
Then, speed of the faster train = 2x m/sec.

Relative speed = (x + 2x) m/sec = 3x m/sec.

(100 + 100)/8 = 3x
24x = 200
x = 25/3

So, speed of the faster train = 50/3 m/sec
speed of the faster train in km/hr is
(50/3) x (18/5) km/hr
= 60 km/hr.
12 years agoHelpfull: Yes(4) No(0)

let the speed of the slower train be x m/sec.

then the speed of the faster train will be 2x m/sec.

now relative speed is(x+2x)m/sec = 3x m/sec.

=>(100+100)/8 =3x

=> 24x = 200

=> x = 25/3

so now the speed of the faster train =50/3 m/sec

=[(50/3)X 18/5)]KMPH

= 60 KMPH
12 years agoHelpfull: Yes(2) No(1)
(200/8 )*(18/5 )*(2/3)=60
12 years agoHelpfull: Yes(0) No(0)

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