IBPS SO Prelims Exam Model Paper 10

Given:
Speed of train X = 108 km/h
Train X overtakes train Y = 50 seconds
Length of train Y = 4 × length of train X
Formula used
Speed = Distance/Time
Calculation:
Let the length of train Y is L2 metre
And the speed of train Y is s m/s
⇒ Length of train X is L1 metre
⇒ Speed of train X = 108 × (

5

18

)
⇒ 30 m/s
According to the question:
⇒ (L1 + L2)/50 = 30 – s
⇒ L1 + L2 = 1500 – 50s ---(1)
And (L1 + L2)/20 = 60 – s
⇒ L1 + L2 = 1200 – 20s ---(2)
From (1) and (2)
⇒ 1500 – 50s = 1200 – 20s
⇒ 1500 – 1200 = -20 s + 50s
⇒ 300 = 30s
⇒

300

30

= s
⇒ 10 m/s = s
⇒ Speed of train Y = 10 m/s
⇒ Length of train Y = 4 × length of train X
⇒ L1 + L2 = 1500 – 50 × 10
⇒ L1 + L2 = 1000
⇒ L1 + ( 4 × L1) = 1000
⇒ 5L1 = 1000
⇒ L1 = 200
⇒ L2 = 200 × 4
⇒ 800 metres
⇒ Length of train Y is 800 metres