Help me answer this ?

Question

a train 1.5miles long take a mintue in a half to clear a tunnel a mile and half long how fast was it going

Answer 1

120 mph

To "clear" a tunnel a train must poke its nose into the tunnel, run until its nose pokes out the far end and then a further distance until its tail leaves the tunnel. That means it must travel a distance made of two parts:  the entire length of the tunnel plus the entire length of the train.

So this train in this tunnel must have gone the 1.5 miles of the tunnel's length plus the 1.5 miles of its own length. That equals 3.0 miles total.

Since it did it in 1.5 minutes, and rate = distance / time, we can say its rate (speed) was (3.0 miles) / (1.5 minutes) = 2.0 miles per minute. Over an hour of 60 minutes that's:  2.0 mi/min * 60 min/hr = 120 miles per hour.

Answer 2

That's not too hard. They try to be sneaky. For it to clear the tunnel, The 1.5m train has to go 3 miles. (1.5 x 2) because it totally isn't in the tunnel, then is totally under the tunnel then it is outside totally. Take the rate = distance/time formula.

rate = 3m/1.5 minute (change this to an hour)

rate = 3mx40/1.5 minute x40 (what you do to the top, do to the bottom of a fraction)

rate = 120 miles/1 hour  

or rather = 120 mph.

Answer 3

60 mph means you are going one mile per minute.. get it?