1. Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively . If they cross each other in 23 seconds, what is the ratio of their speeds?
1. Insufficient data
2. 3 : 1
3. 1 : 3
4. 3 : 2
Answer & Explanation Answer:- 4 Explanation :- Let the speeds of First trains be x m/sec and That of Second train be y m/sec 2. A jogger is running at 9 kmph alongside a railway track in 240 meters ahead of the engine of a 120 meters long train . The train is running at 45 kmph in the same direction. how much time does it take for the train to pass the jogger? Answer & Explanation Answer:- 2 Explanation :- Relative Speed = (45-9) = 36 kmph = 36*(5/18) = 10 m/sec 3. Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. If the faster train passes the slower train in 36 seconds,what is the length of each train? Answer & Explanation Answer:- 4 Explanation :- Lets suppose the length of each train is x meter 4. Two trains having length of 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions (on parallel tracks). The time which they take to cross each other, is Answer & Explanation Answer:- 1 Explanation :- Relative speed = (60 + 40) km/hr =[ 100 x ( 5 / 18 ) ] m/sec = ( 250 /9 ) m/sec. 5. Two trains are moving in opposite directions with speed of 60 km/hr and 90 km/hr respectively. Their lengths are 1.10 km and 0.9 km respectively. the slower train cross the faster train in — seconds Answer & Explanation Answer:- 2 Explanation :- Relative Speed = 60 + 90 = 150 km/h = 150 (5/18) m/s = 125/3 m/s
distance = speed * time]
Then,
Length of the first train = 27x metres,
Length of the second train = 17y metres.
(27x +17y)/(x + y) = 23
27x + 17y = 23x +23y
4x = 6y
x/y = 3/2
1. 46
2. 36
3. 18
4. 22
Distance to cover = 240 + 120 = 360 metres
Time = Distance/Speed
Time = 360/10 = 36 sec
1. 88
2. 70
3. 62
4. 50
Therefore , Distance = x+x = 2x
Relative Speed = 46-36 = 10 km/hr = 10*(5/18) = 25/9 m/sec
Distance = Speed*Time
2x = (25/9) * 36
2x = 100 => x = 50
Therefore , Length of each train = 50 metres
1. 10.8 s
2. 12 s
3. 9.8 s
4. 8 s
Distance covered = (140 + 160) m = 300 m.
Time = [ 300 x ( 9/250 ) ] sec = ( 54/ 5 ) sec = 10.8 sec.
1. 56
2. 48
3. 47
4. 26
Distance covered = (1.10 + 0.9) km = 2 km = 2000 metres
Time = distance/speed
The slower train cross the faster train in = 2000 /(125/3) = 2000 * 3/125 = 48 sec