LIC AAO Model Paper 9 with solutions for free online practice

Let the length of train A be x metre.
∴ Length of train B =

x

2

metre
Speed of train A = 126 kmph
= (126×5/{18}) m/sec
= 35 m/sec
Speed of train B = 90 kmph.
= (90×

5

18

) m/secc
= 25 m/sec
∴ Relative speed of A =

Length‌of‌trains‌A‌and‌B

Time‌taken‌in‌crossing

⇒ 35 + 25 =

x+ x 2

9

⇒ 60 × 9 =

3x

2

⇒ 3x = 90 × 12
⇒ x =

90×12

3

= 360 metre
∴ Time taken in crossing the platform

Length‌of‌train‌A‌and‌platform

Speed‌of‌train‌A

= (

360+690

35

) seconds
=

1050

35

seconds
= 30 seconds