Discuss Forum
1.
A train of length 150 m takes 10 seconds to cross another train 100 m long coming from the opposite direction . If the speed of first train is 30 km / hr, what is the speed of second train?
- A. 48km /hr
- B. 48km /hr
- C. 48km /hr
- D. 48km /hr
Answer: Option C
Explanation:
Take the speed of the second train =
x
km/hr
They will have to cover a distance = sum of the lengths of the trains ( 150 + 100 = 250 m = 0.25 km )
Obtain their relative speed( x + 30 ) km/h & find out the time taken ( 10 sec = 10/3600 hr )
Equate it to 10s and solve for
( x + 30 ) =( 0.25/ 10 ) * 3600
x = 60 km/hr
x
km/hr
They will have to cover a distance = sum of the lengths of the trains ( 150 + 100 = 250 m = 0.25 km )
Obtain their relative speed( x + 30 ) km/h & find out the time taken ( 10 sec = 10/3600 hr )
Equate it to 10s and solve for
( x + 30 ) =( 0.25/ 10 ) * 3600
x = 60 km/hr
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