The speed of the flow of a river is 3 km/h * r . A motorboat goes 12km downstream and comes back in a total time of 3 hours. Find the speed of the motorboat in still water. (the speed of flow of water is less than the speed of the boat)
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The speed of the flow of a river is 3 km/h * r . A motorboat goes 12km downstream and comes back in a total time of 3 hours. Find the speed of the motorboat in still water. (the speed of flow of water is less than the speed of the boat)
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Step-by-step explanation:
Letspeedofstream=xkm/hr
then(
9+x
15
)+(
9−x
15
)=3+(
4
3
)hour
15(
81−x
2
9−x+9+x
)=(
4
15
)
72=81−x
2
∴x
2
=81−72
∴x=3km/hr