Aptitude contest - 78

[HELP]

1. A train overtakes two persons who are walking in the same
direction in which the train is going, at the rate of 2 kmph and 4 kmph
and passes them completely in 9 and seconds respectively. The length of
the train is :

(a) 45 m

(b) 50 m

(c) 54 m

(d) 72 m



2. A train overtakes two persons walking along a railway track. The
first one walks 4.5 km/hr. The other one walks at 5.4
km/hr. The train needs 8.4 and 8.5 seconds respectively to
overtake them. What is the speed of the train if both the persons also
walking in the same direction as the train?



(a) 66 km/hr

(b) 72 km/hr

(c) 78 km/hr

(d) 81 km/hr



3. 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/hr

(b) 45 km/hr

(c) 60 km/hr

(d) 75 km/hr



4. A train 150 m long passes a km stone in 15 seconds and another train
of the same length travelling in opposite direction in 8 seconds. The
speed of the second train is



(a) 60 km/hr

(b) 66 km/hr

(c) 72 km/hr

(d) 99 km/hr



5. A train travelling at 48 kmph completely crosses another train
having half its length and travelling in opposite direction at 42
kmph, in 12 seconds. It also passes a railway bplatform in 45
seconds. The length of the platform is



(a) 400 m

(b) 450 m

(c) 560 m

(d) 600 m

Edited by: HELP

[Anusha_j]

3. 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/hr
(b) 45 km/hr
(c) 60 km/hr5.

(d) 75 km/hr

ans : 30 km/hr

(2v+v) 8 = 100

v = 100/24 m/sec 0r 15 km/r

faster train (2v) = 30km/hr

5. A train travelling at 48 kmph completely crosses another train having half its length and travelling in opposite direction at 42 kmph, in 12 seconds. It also passes a railway bplatform in 45 seconds. The length of the platform is

(a) 400 m
(b) 450 m
(c) 560 m
(d) 600 m

ans: 400m

3l/2 = (48+42)12 * 5/18

length of train = 200m

(200+ L ) = 48 * 45 * 5/18

length of platform = 400m

[murari]

nice approach