Question

The length of two trains (A and B) is 270 m and 720 m, respectively. If they are going in the same direction, Train A takes 55
seconds to pass Train B completely and if they are going in opposite directions, they pass each other completely in 9 seconds. Find
the speed of train B?
​

Answer 1

Step-by-step explanation:

let the speed of the train A be x m/s and B be y m/s...total length of the trains is 270+720=990m

so x+y= 990/9=110 (opposite direction)

and x-y= 990/55=18 (same direction)..

solving it we get x=64 and y=46..

so speed of train B is 46 m/s= 165.6 km/h

Answer 2

Answer:

16 m/sec.

Step-by-step explanation:

55( $v_{A}$ - $v_{B}$ ) = 990 ⇔  (1)

9( $v_{A}$ + $v_{B}$ ) = 450 ⇔  (2)

(1) + (2)

2$v_{A}$ = 68 ⇒  

34 + $v_{B}$ = 50 ⇒ 16 m/sec.