A train passes a pole in 10 secs & a bridge of length 2km in 110 secs. What is its speed?

While train is passing
pole

Let length of train
=x

Length of pole is
negligible

=> Total
distance=x

Time = 10
secs

=> Speed = Distance/Time= x/10
m/s

While train is passing
station

Total distance = x + 2000
metre

Time = 110 sec

Speed =
(x + 2000)/110

Assuming the  speed of train to be
constant

=> x/10 =
(x+2000)/110

=> 11x =
x+2000

=> 11x -x =
2000

=> x = 2000/10 = 200
metres

=> Speed = x/10 =
200/10

=> Speed = 20 m/s