TIME AND TRAINS

Thanks Ginger :)

Look here

http://web2.0calc.com/questions/i-came-across-this-question-and-didn-t-know-how-to-solve-it

For

Sir Alan’s quick and compact answer.

Miss Melody’s Ideograph, comprehensible by non-genetically enhanced chimps. (Most of them, anyway).

Herr Heureak’s formal presentation that meets the demands of even the most strict math teacher—except for Sister Alice who taught eighth grade math.  (Nothing made that witch happy –except pain and suffering).

GA

Note that the combined rates of the ttains  = 120kph  = 1/30 km / s

And the length of the trains are 1/2 km ......and the other is 2/3 as long = 1/3 km,...so....

The problem boils down to the number of seconds it takes the rear of the longer train to travel [ 1/2 + 1/3] km  = 5/6 km

And   D /R  = T     ....so....        [5/6]km / [ 1/30 km/ s]   =  [5 * 30 ] / 6     =   25 seconds to completely pass each other

CPhill: You made a slight mistake in combining the lengths of the 2 trains: one is 1/2km long, and the other 2/3km long. Their combined length=1/2 + 2/3 =1 1/6 km, not 5/6km. Thereby, the final answer will be (1 1/6) / (1/30) =35 seconds.

The problem actually states that one train is 1/2 km long and the other is 2/3 as long  =  1/3 km........?????

I believe the person that posted it made a mistake in stating the question. Here is exactly the same question posed in Feb. 2015:

Feb 17, 2015 10:43 AM+5    

Two trains, each traveling at 60 kph [1 kilometer/minute] are on parallel tracks heading toward one another. One train is one-half kilometer long and the other train is two-thirds kilometer long. The fronts of the two trains pass the same point A at the same time. How many seconds does it take for the two trains to completely pass each other?

Of course, you can only go by what you are given!!!.

It’s great to have trolls back again.  

The guest is not a troll. He says he’s a banker, but really, he’s a mutant gnome. Most gnomes stand around giving the place an odd look.  This one talks though. When E.F. Gnome talks, people listen, but all they ever hear is blarney.   

http://web2.0calc.com/questions/a-farmer-s-dilemma

HaHaHaHa Well it’s good to have one troll around again.  

When E.F. Gnome talks, people listen. HaHaHaHaHa that is really good!