AFCAT I 2015 Solved Paper

Speed = distance\/time
1km∕hr=5∕18m∕sec
1m∕sec=18∕5km∕hr

Let speed of train be xm∕sec and length of train be y‌‌m, then According to the question
‌x=

(200+y)

10

‌‌−(1)
‌x=

y

5

‌‌−(2)
From equation (1) and equation (2)

y

5

=

(200+y)

10

⇒2y=200+y
⇒2y−y=200
⇒y=200
Length of train is 200 m
From equation (2)
‌x=

200

5

⇒x=40m∕sec
⇒x=40×

18

5

⇒x=144km∕hr
∴ Speed of train is 144km∕hr.