Sunday, April 1, 2007

"MATH PROBLEM OF THE DAY"

A train of length l, traveling at a constant velocity, passes a pole in t seconds. If the same train
traveling at the same velocity passes a platform in 3t seconds, then the length of the platform is
(A) 0.5l
(B) l
(C) 1.5l
(D) 2l
(E) 3l

9 comments:

  1. its D yaar...

    explanation~>

    vt=l...(1)
    3vt=(l+p)
    so,2vt=p

    so,2*t*l/t=p
    so,2l=p

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  2. sorry itz not d itz "e"

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  3. the velocity = l/t
    the time taken to cross the platform = 3t
    therefore the length of the platform = l/t x 3t
    = 3l
    hence e is correct

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  4. sorry ..
    d is correct
    because the length of the train is to be taken into consideration
    3l is (l+y)
    y is the distance of the platform
    so y = (3l-l)
    = 2l

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