Question

a train 1000 meters long travels through a 3000m tunnel in 30 seconds

Answer 1

Answer:

A train 1000 m long travels through a 3000 m tunnel. If 30 seconds elapse from the time the last car enters the tunnel until the time when the engine emerges from the other end, the speed of the train, in meters per second, is:

a 100/3 b 200/3 c 100 d 1000 e None of these

Found 2 solutions by rfer, Edwin McCravy:Answer by rfer(16316)   (Show Source): You can put this solution on YOUR website!

2000m / 30 seconds, or 200/3, (b)

Answer by Edwin McCravy(18851)   (Show Source): You can put this solution on YOUR website!

Edwin's solution:

A train 1000 m long travels through a 3000 m tunnel. If 30 seconds elapse from the time the last car enters the tunnel until the time when the engine emerges from the other end, the speed of the train, in meters per second, is:

a 100/3 b 200/3 c 100 d 1000 e None of these

Let this line be the track inside the tunnel with the

1000, 2000, and 3000 meter markers:

Put the train just inside the tunnel, with the engine

at the 1000 meter marker, and the last car at the 0

meter marker, the left end of the tunnel.

Now when the engine is at the 3000 meter marker which

is the right end of the tunnel, we have this:

So the engine only traveled 2000 meters, from

the 1000 meter marker to the 3000 meter marker,

So the engine has traveled 2000 meters.

Since 

Edwin