Question

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A boat can row 1 km with stream in 10 minutes and 1 km against stream in 20 minutes. what is the speed of the boat in stll water?

a.1.5 km/hr

b.3 km/hr

c.3.4 km/hr

d.4.5 km/hr

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$= i \: wil \: give \: multiple \: thanks \: in \: correct \: answer \\ = and \: i \: mark \: brainlist$
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Answer 1

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A boat can row 1 km with stream in 10 minutes and 1 km against stream in 20 minutes. what is the speed of the boat in stll water?

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b)4.5 km/h

Solution

Let the speed in still water = x

Let the speed in stream = y

so the speed in downsteam = x + y

but as it is given in question

speed in downstream =

= 6 km/h = x + y

speed in upstream = x - y

so from this

x + y = 6 {i}

x - y = 3 {ii}

on {i} + {ii}

x = 4.5 (now putting this value in {i} )

4.5 + y = 6

y = 6 - 4.5

= 2.5

so speed in still water 4.5 k/h

speed of stream 2.5 km/h

Answer 2

Answer:

Let speed of stream in still water =x

And speed of stream = y

Thus

Speed with stream =x+ y

And speed against stream= x- y

Speed = distance/time

Thus

x + y=1/(10/60)

x+y =6……(1)

and

x - y =1/(20/60)

x-y =3……..(2)

adding (1) and(2)

2x=9

x=4.5

thus speed of boat in still water = 4.5 km/h

Step-by-step explanation: