Question

A man standing on a platform 225 m long notices that a train travelling at a uniform speed passes him in 6 s and passes by the platform in 21s.find the length of train and speed of train

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Answer 1

Answer:

let the speed of train be'v' and legnth be 'x'

v=225+x/21. (i)

v=x/6. (ii)

from equation I and ii

225+x/21=x/6

6(225+x)=21x

1350+6x=21x

21x-6x=1350

15x=1350

x=1350/15

x=90

speed of train = 15kmph

legnth of train = 90m