Question

A boat makes a return journey from point A to point B and back in 5 hours 36 minutes. One way it travels with the stream and on the return it travels against the stream. If the speed of the stream increases by 2 km/hr, the return journey takes 9 hours 20 minutes, What is the speed of the boat in still water? (The distance between A and B is 16 km.)
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Answer 1

Answer:

speed =

time

distance

⟹time=

speed

distance

let speed of flow=x

speed in ascent=speed of boat in still water + speed of water flow

speed in decent=speed of boat in still water− speed of water flow

let time of decent=y

⟹time of ascent=y−2.5

time of ascent=

3+x

10

time of decent=

3−x

10

⟹

3+x

10

=

3−x

10

−2.5

10(3−x)−10(3+x)=−2.5(3+x)(3−x)

⟹x

2

+8x−9=0

x=1(∵x is positive)

given time of ascent =2

2=

actual speed of boat +1

10

⟹ actual speed of boat required is 4km/hr

Step-by-step explanation:

may this helps you ☺️☺️☺️☺️