A train approaches a tunnel AB. Inside the tunnel is a cat located at a point that is 3/8 of the distance AB measured from the entrance A. When the train whistles the cat runs. If the cat moves to the entrance of the tunnel A, the train catches the cat exactly at the entrance. If the cat moves to the exit B, the train catches the cat at exactly the exit. What is the ratio of speed of train and cat ?
Let the length of the tunnel be x and distance of the train to entrance A be y. Let the speeds of train and cat be t and c respectively.
Hence, when the cat runs 3x/8, the train covers y.
=> (3x/8)/c = y/t --- (1)
When the cat runs 5x/8 to the other end, the train covers x+y
=>(5x/8)/c = (x+y)/t ---(2)
Taking ratio of (1) to (2)
3/5 = y/(x+y) => 3x = 2y ---(3)
Substituting (3) in (1)
(2y/8)/c = y/t
=> t = 4c
Hence the ratio t:c is 4:1.
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