Tuesday, 15 October 2013

Aptitude Questions

1. 
A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
A.120 metresB.180 metres
C.324 metresD.150 metres


 Answer: Option D
Explanation:
Speed=60 x5m/sec=50m/sec.
183
Length of the train = (Speed x Time) =50x 9m = 150 m.
3
2. 
A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:
A.45 km/hrB.50 km/hr
C.54 km/hrD.55 km/hr
Answer: Option B
Explanation:

Speed of the train relative to man =125m/sec
10

   =25m/sec.
2

   =25x18km/hr
25

   = 45 km/hr.
Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
 x - 5 = 45          x = 50 km/hr.

3. 
The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:
A.200 mB.225 m
C.245 mD.250 m

Answer: Option C
Explanation:

Speed =45 x5m/sec=25m/sec.
182

Time = 30 sec.
Let the length of bridge be x metres.
Then,130 + x=25
302

 2(130 + x) = 750
 x = 245 m.

4. 
Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:
A.1 : 3B.3 : 2
C.3 : 4D.None of these

Answer: Option B
Explanation:

Let the speeds of the two trains be x m/sec and y m/sec respectively.
Then, length of the first train = 27x metres,
and length of the second train = 17y metres.
27x + 17y= 23
xy

 27x + 17y = 23x + 23y
 4x = 6y
x=3.
y2

5. 
A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
A.120 mB.240 m
C.300 mD.None of these

Answer: Option B
Explanation:

Speed =54 x5m/sec = 15 m/sec.
18

Length of the train = (15 x 20)m = 300 m.
Let the length of the platform be x metres.
Then,x + 300= 15
36

 x + 300 = 540
 x = 240 m.

6. 
A train 240 m long passes a pole in 24 seconds. How long will it take to pass a platform 650 m long?
A.65 secB.89 sec
C.100 secD.150 sec

Answer: Option B
Explanation:

Speed =240m/sec = 10 m/sec.
24

 Required time =240 + 650sec = 89 sec.
10

7. 
Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is:
A.50 mB.72 m
C.80 mD.82 m


Answer: Option A
Explanation:

Let the length of each train be x metres.
Then, distance covered = 2x metres.
Relative speed = (46 - 36) km/hr
   =10 x5m/sec
18

   =25m/sec
9

2x=25
369

 2x = 100
 x = 50.

8. 
A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
A.40 secB.42 sec
C.45 secD.48 sec


Answer: Option A
Explanation:

Formula for converting from km/hr to m/s:   X km/hr =X x5m/s.
18

Therefore, Speed =45 x5m/sec=25m/sec.
182

Total distance to be covered = (360 + 140) m = 500 m.
Formula for finding Time =Distance
Speed

 Required time =500 x 2sec= 40 sec.
25

9. 
Two trains are moving in opposite directions @ 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 0.9 km respectively. The time taken by the slower train to cross the faster train in seconds is:
A.36B.45
C.48D.49


Answer: Option C
Explanation:

Relative speed = (60+ 90) km/hr
   =150 x5m/sec
18

   =125m/sec.
3

Distance covered = (1.10 + 0.9) km = 2 km = 2000 m.
Required time =2000 x3sec = 48 sec.
125

10. 
A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
A.3.6 secB.18 sec
C.36 secD.72 sec


Answer: Option C
Explanation:

Speed of train relative to jogger = (45 - 9) km/hr = 36 km/hr.
   =36 x5m/sec
18

   = 10 m/sec.
Distance to be covered = (240 + 120) m = 360 m.
 Time taken =360sec= 36 sec.
10


11. 
A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?
A.230 mB.240 m
C.260 mD.320 m
E.None of these

Answer: Option A
Explanation:

Relative speed = (120 + 80) km/hr
   =200 x5m/sec
18

   =500m/sec.
9

Let the length of the other train be x metres.
Then,x + 270=500
99

 x + 270 = 500
 x = 230.

12. 
A goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 26 seconds. What is the length of the goods train?
A.230 mB.240 m
C.260 mD.270 m


Answer: Option D
Explanation:

Speed =72 x5m/sec= 20 m/sec.
18

Time = 26 sec.
Let the length of the train be x metres.
Then,x + 250= 20
26

 x + 250 = 520
 x = 270.

13. 
Two trains, each 100 m 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:
A.30 km/hrB.45 km/hr
C.60 km/hrD.75 km/hr

Answer: Option C
Explanation:

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)= 3x
8

 24x = 200
 x =25.
3

So, speed of the faster train =50m/sec
3

   =50x18km/hr
35

   = 60 km/hr.

14. 
Two trains 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 (in seconds) which they take to cross each other, is:
A.9B.9.6
C.10D.10.8


Answer: Option D
Explanation:

Relative speed = (60 + 40) km/hr =100 x5m/sec=250m/sec.
189

Distance covered in crossing each other = (140 + 160) m = 300 m.
Required time =300 x9sec=54sec = 10.8 sec.
2505

15. 
A train 110 metres long is running with a speed of 60 kmph. In what time will it pass a man who is running at 6 kmph in the direction opposite to that in which the train is going?
A.5 secB.6 sec
C.7 secD.10 sec