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Q:

Two trains started at the same time, one from A to B and the other from B to A . If they arrived at B and A respectively 4 hours and 9 hours after they passed each other the ratio of the speeds of the two trains was 

A) 2:1 B) 3:2
C) 4:3 D) 5:4

Answer:   B) 3:2

Explanation:

Note : If two trains (or bodies) start at the same time from points A and B towards each other and after crossing they take a and b sec in reaching B and A respectively, then: (A's speed) : (B's speed) = (b : a)

Therefore, Ratio of the speeds of two trains =  = 3 : 2

Q:

Two goods trains each 520 m long, are running in opposite directions on parallel tracks. Their speeds are 42 km/hr and 36 km/hr respectively. Find the time taken by the slower train to cross the driver of the faster one ?

A) 60 sec B) 48 sec
C) 45 sec D) 34 sec
 
Answer & Explanation Answer: B) 48 sec

Explanation:

Relative speed = 42 + 36 = 78 km/hr =  m/s
Distance = (520 + 520) =1040 mts.
Time = = 48 sec

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4 107
Q:

Two trains are running at 60 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 6 seconds. What is the length of the fast train ?

      

A) Option A B) Option B
C) Option C D) Option D
 
Answer & Explanation Answer: A) Option A

Explanation:

As Trains are moving in same direction,
Relative Speed = 60-20 = 40 kmph
  m/sec

Length of Train= Speed * Time

Length = 

 

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5 98
Q:

Length of train is 170 meters and speed of train is 63 km/hour. This train can pass a bridge in 30 seconds, then find the length of the bridge.

A) 355 mts B) 325 mts
C) 365 mts D) 312 mts
 
Answer & Explanation Answer: A) 355 mts

Explanation:

Given speed = 63 km/hr =  m/s
Let the length of the bridge = x mts
Given time taken to cover the distance of (170 + x)mts is 30 sec.
We know speed =  m/s

 

 x = 355 mts.

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Q:

A train running at the speed of 40 km/hr crosses a signal pole in 9 seconds. Find the length of the train ?

A) 90 mts B) 150 mts
C) 120 mts D) 100 mts
 
Answer & Explanation Answer: D) 100 mts

Explanation:

We know that  

 distance= speed * time
 d = 

  d= 100 mts.

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4 102
Q:

A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is :

A) 9.5 km/hr B) 10 km/hr
C) 10.5 km/hr D) 11 km/hr
 
Answer & Explanation Answer: B) 10 km/hr

Explanation:

Man's rate in still water = (15 - 2.5) km/hr = 12.5 km/hr.

 Man's rate against the current = (12.5 - 2.5) = 10 km/hr.

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