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a boat takes 6 hours to travel 24 km upstream and 36km downstream and it takes 9 hours to travel 40 km upstream and 48 km downstre

By Melody

a boat takes 6 hours to travel 24 km upstream and 36km downstream and it takes 9 hours to travel 40 km upstream and 48 km downstream find the speed of the boat in still water and the speed of the stream​

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Melody

A -mile-long obstacle course is divided into equal sections, as shown. There is an obstacle at the beginning of each section.

Sub-English MM50
Answer the following questions-
1. You have lost your watch somewhere in the school premises. Besides

2 thoughts on “a boat takes 6 hours to travel 24 km upstream and 36km downstream and it takes 9 hours to travel 40 km upstream and 48 km downstre”

  2. 6 hours to travel 24 km upstream and 36km downstream

    9 hours to travel 40 km upstream and 48 km downstream

    let speed of boat = x

    and

    speed of stream = y

    24/6 = 4 km/h = x-y ( upstream)

    36/6 = 6 km/h = x+y (down)

    so x+y/x-y = 6/4

    4x+4y = 6x-6y

    10y=2x

    x=5y

    so. x+y=6=5y+y=6y

    y=1

    then x= 5

    same for the next section also

    40/9 = x-y. and

    48/9 = x+y

    so

    x+y=48/9. (1)

    x-y= 40/9. (2)

    (1)/(2) = x+y/x-y = 48/9. ÷ 40/9 = 48/40 = 12/10=5/6

    so

    6x+6y=5x-5y

    x= -11y

    it makes either X or y negative which is not possible in case of speed

    Reply

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